US5325218A - Cholesteric polarizer for liquid crystal display and overhead projector - Google Patents

Cholesteric polarizer for liquid crystal display and overhead projector Download PDF

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US5325218A
US5325218A US07/999,230 US99923092A US5325218A US 5325218 A US5325218 A US 5325218A US 99923092 A US99923092 A US 99923092A US 5325218 A US5325218 A US 5325218A
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light
liquid crystal
crystal cell
quarter
interposed
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US07/999,230
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Stephen J. Willett
Gary L. Tritle
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3M Co
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Minnesota Mining and Manufacturing Co
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Assigned to MINNESOTA MINING AND MANUFACTURING COMPANY reassignment MINNESOTA MINING AND MANUFACTURING COMPANY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: TRITLE, GARY L., WILLETT, STEPHEN J.
Priority to US07/999,230 priority Critical patent/US5325218A/en
Priority to TW82100206A priority patent/TW273600B/zh
Priority to JP6516003A priority patent/JPH08505480A/en
Priority to KR1019950702688A priority patent/KR960700458A/en
Priority to EP94903583A priority patent/EP0677178B1/en
Priority to PCT/US1993/012034 priority patent/WO1994016355A1/en
Priority to DE69318729T priority patent/DE69318729T2/en
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    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1347Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
    • G02F1/13471Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells
    • G02F1/13473Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells for wavelength filtering or for colour display without the use of colour mosaic filters
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133509Filters, e.g. light shielding masks
    • G02F1/133514Colour filters
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133528Polarisers
    • G02F1/133533Colour selective polarisers
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133528Polarisers
    • G02F1/133536Reflective polarizers
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133528Polarisers
    • G02F1/133543Cholesteric polarisers
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133621Illuminating devices providing coloured light
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2201/00Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
    • G02F2201/34Constructional arrangements not provided for in groups G02F1/00 - G02F7/00 reflector
    • G02F2201/343Constructional arrangements not provided for in groups G02F1/00 - G02F7/00 reflector cholesteric liquid crystal reflector
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S353/00Optics: image projectors
    • Y10S353/03Transparent
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S353/00Optics: image projectors
    • Y10S353/05Transparency holder accessories

Definitions

  • the present invention generally relates to optical polarizers, and more particularly to a novel liquid crystal display panel and an overhead projector which incorporate tuned cholesteric polarizers.
  • Liquid crystal display (LCD) panels generally employ one of several different types of polarizers, including dyed stretched polymeric (neutral and dichroic), cholesteric or thin-film polarizers.
  • polarizers including dyed stretched polymeric (neutral and dichroic), cholesteric or thin-film polarizers.
  • FIG. 1 discloses an LCD panel (depicted in FIG. 1) which uses both neutral polarizers 1 and dichroic polarizers 2 in a stacked arrangement.
  • the dichroic dyes and associated liquid crystal layers 3 are selected to provide desired optical responses in order to yield the three primary subtractive colors, magenta, cyan and yellow.
  • dichroic dyed polarizers Another drawback to dichroic dyed polarizers is that their spectral cutoffs are limited by the dyes themselves. In many uses, such as stacked, color supertwisted nematic (STN) LCD panels, these cutoffs are not as sharp as would be desired, and their use results in less than ideal color purity and brightness or, alternatively, necessitates use of neutral polarizers instead.
  • STN color supertwisted nematic
  • Cholesteric polarizers have sharper spectral cutoffs which can be employed to improve these uses, and are reflective rather than absorptive but, prior to the present invention, cholesteric polarizers have not been incorporated into flat panel LCD designs. These polarizers utilize liquid crystal material in which the elongated molecules are parallel to each other within the plane of a layer, but the direction of orientation twists slightly from layer to layer to form a helix through the thickness of the polarizer. Cholesteric polarizers are either right- or left-handed and, depending upon this handedness, transmit or reflect circularly polarized light in a narrow optical bandwidth. As suggested by Schadt et al. (see SID 1990 Symposium Digest pp.
  • cholesteric polarizers are used to selectively block one of two images in a head-up/head-down display. While that patent further discloses the use of multiple polarizers to selectively block discrete color images, the polarizers are never used for manipulating the color tone of a single image.
  • the configuration of the '410 device is also generally incompatible with that of an LCD panel. See additionally U.S. Pat. No. 5,050,966. It would, therefore, be desirable and advantageous to devise an LCD panel which incorporates cholesteric polarizers, but provides high efficiency, wide aperture transmission of the light for stacked LCD panel designs.
  • a stacked liquid crystal display panel having a plurality of cholesteric polarizers forming color and neutral filters, interposed between supertwisted, nematic (STN) liquid crystal cells.
  • Quarter-wave plates are used to convert the circularly polarized light into linearly polarized light before entry into the STN layers.
  • Fresnel lenses are used to collimate and condense the light, increasing the efficiency of the panel.
  • a subtractive scheme is used to blend colors from the three STN layers, the color cholesteric filters will correspond to two primary subtractive colors; this means that each filter will include one or more polarizers tuned to the bandwidth of a single primary additive color.
  • each filter will correspond to a primary additive color; this means that each filter will include two or more polarizers tuned to two bandwidths of the complementary primary additive colors.
  • no neutral polarizers are used.
  • the cholesteric polarizers of the present invention may also be incorporated into an overhead projector to yield a high output polarized light source.
  • a plurality of polarizers are selected, according to their bandwidths, to cover the entire visible spectrum, and are combined with a single quarter-wave plate and two Fresnel lenses.
  • a light source which includes a back reflector may be used to recycle that portion of light reflected by the polarizers.
  • FIG. 1 is an exploded perspective view of a prior art, color, stacked STN LCD panel using neutral and dichroic polaroid polarizers;
  • FIG. 2 is a schematic side view of one embodiment of the color LCD panel of the present invention, using cholesteric color and neutral filters;
  • FIG. 3 is a schematic side view of another embodiment of the color LCD panel of the present invention, using no neutral filters;
  • FIG. 4 is a schematic side view of still another embodiment of the color LCD panel of the present invention, in which the first filter polarizes light in the entire visible spectrum;
  • FIG. 5 is a schematic side view of yet another embodiment of the color LCD panel of the present invention, utilizing an additive color scheme
  • FIG. 6 is a perspective view of one embodiment of the high output polarized light overhead projector of the present invention.
  • FIG. 7 is a schematic side view of the cholesteric filter and light source located in the overhead projector of the present invention.
  • LCD panel 10 generally comprises a plurality of reflective polarizing filters 12, 14, 16 and 18, a plurality of liquid crystal cells 20, 22 and 24, and two Fresnel lenses 26 and 28.
  • Lens 26 is used to collect and collimate the light for the stacked arrangement, while lens 28 is used to condense the light toward other optical components (such as the projector head of the overhead projector described in FIG. 6).
  • Each of the filters includes one or more quarter-wave plates 30, and at least one cholesteric circular polarizer.
  • FIG. 2 which utilizes a subtractive color scheme similar to the prior art device of FIG.
  • filter 12 preferably includes a single cholesteric polarizer 12a which is tuned to red wavelengths (i.e., an approximate bandwidth of 600 nm to 700 nm).
  • a cholesteric polarizer will pass all green and blue hues, but will pass only one polarization component of red. The component to be passed depends upon the handedness of the cholesteric molecules in polarizer 12a. If those molecules are right-handed, then right-handed (RH) circularly polarized (CP) light will be reflected, but left-handed (LH) CP light will be transmitted. Transmission and reflection of these components is nearly 100% efficient.
  • RH right-handed
  • CP circularly polarized
  • LH left-handed
  • filter 12 is combined with cell 20 to create a cyan filter.
  • red light passing through polarizer 12a is split into two circularly polarized components, with only one of those components passing through polarizer 12a.
  • the first quarter-wave plate 30 then converts this circularly polarized light into linearly polarized light so that it may be further regulated by cell 20.
  • Cell 20 is tuned to select or deselect (reject) passage of this red light by modulating the phase of the linearly polarized light (rotating the angle of polarization), as discussed in U.S. Pat. No. 4,917,465 (see FIG. 9 of that patent), which is hereby incorporated. Tuning is accomplished by choosing an appropriate thickness for the liquid crystal layer of cell 20, and by choosing a material which has an appropriate optical anisotropy. The preferred material is a supertwisted nematic (STN) liquid crystal.
  • STN supertwisted nematic
  • Filter 14 is neutral and includes three separate cholesteric polarizers 14a, 14b and 14c which are tuned, respectively, to the three primary colors red, green and blue.
  • a first quarter-wave plate 30 in filter 14 is used to convert the linear polarized light to circular polarized light
  • a second quarter-wave plate 30 in filter 14 is used to convert the circular polarized light into linear polarized light.
  • Blue light passing through filter 14 is selected or deselected by yellow cell 22. Since all light outside of each polarizer's bandwidth completely passes through the polarizer, several such polarizers can be stacked in series without affecting the optical performance of each. In this regard, it is understood that separate polarizers are needed for a neutral filter in order to cover the entire visible spectrum. As discussed further below, more than three polarizers may be needed if the bandwidths are particularly narrow or, conversely, it is conceivable that a single polarizer could be devised which would have a sufficiently large bandwidth to cover the visible spectrum.
  • Filter 16 is essentially identical to filter 14, and includes three cholesteric polarizers 16a, 16b and 16c which are also tuned, respectively, to the three primary colors red, green and blue. Green light passing through filter 14 is selected/deselected by magenta cell 24. Another pair of quarter-wave plates 30 are used as in filter 14. Filter 18, which includes a single cholesteric polarizer 18a tuned to green, and another quarter-wave plate 30 interposed between polarizer 18a and cell 24, acts as an analyzer to render the modulation pattern in the outgoing light visible.
  • FIG. 3 that figure depicts another embodiment 32 of an LCD panel made according to the present invention.
  • Panel 32 includes the same rear (cyan) and front (magenta) filters 12 and 18, but neutral filters 14 and 16 have been replaced, respectively, with green and red filters 34 and 36.
  • Filter 34 includes two cholesteric polarizers 34a and 34b tuned, respectively, to red and blue
  • filter 36 includes two cholesteric polarizers 36a and 36b tuned, respectively, to green and blue. Both filters use two quarter-wave plates each, and the same cells 20, 22 and 24 may be used in panel 32.
  • This embodiment is considered most preferable since panel 32 combines high quality color polarizers with the greatest light transmission possible in a stacked, color STN LCD panel.
  • FIG. 4 Yet another embodiment 38 of an alternative LCD panel is shown in FIG. 4.
  • This embodiment is essentially identical to panel 32 except for the use of a different rear Fresnel lens 40 and a different first filter 42.
  • Panel 38 is designed to take advantage of the reflective properties of cholesteric polarizers, and is particularly useful in display systems having a point light source 44, such as an overhead projector. Accordingly, Fresnel lens 40 should be a convergent lens.
  • Filter 42 is neutral, in order to allow for recycling of that portion of the light which is reflected by the polarizers 42a, 42b and 42c. This reflected light may be recycled by providing a mirror 46 or other reflective surface proximate to light source 44.
  • Circular, cholesteric polarizers may also be used to improve the performance (color purity) of other multilayer color LCD panels, such as those depicted in U.S. Pat. Nos. 4,416,514 and 4,838,655.
  • cholesteric polarizers may be used to create an additive LCD panel 48, as illustrated in FIG. 5.
  • This panel is also very similar to the foregoing panels in that it employs the same LCD cells 20, 22 and 24, a plurality of quarter-wave plates 30, and a pair of Fresnel lenses 26 and 28. It also uses the same intermediate filters 34 and 36, but the first filter 50 is now a blue filter, having two cholesteric polarizers 50a and 50b tuned to red and green, respectively.
  • the analyzer 52 in any of the foregoing embodiments may be a neutral (stretch polymeric) polarizer rather than a cholesteric polarizer combined with a quarter-wave plate.
  • the order of the filters (as well as the order of the component polarizers in each filter) may vary without affecting the panel's output.
  • cholesteric polarizers can replace one, several, or all of the dyed dichroic and neutral polarizers of the prior art panels.
  • the present invention could be applied to hybrid additive color LCD systems, such as the guest-host twisted nematic (TN) system of U.S. Pat. No. 4,838,655.
  • the LCD cells to be used should rotate linear polarized light between 90° (when off) and 0° (when fully on), and may be chosen from TN, ferroelectric, or other LCD types.
  • Such cells include TN cells that act as a half wave retarder, instead of the conventional TN waveguiding mode, and electrically-controlled birefringent ECB LCD's, also known as DAP LCD's (deformed vertically-aligned phase).
  • OHP 60 includes many conventional parts, such as a base 62 having a stage area 64 (typically a glass sheet 66), a projector head 68 having a projection lens 70 and mirror 72, and an arm 74 attached to base 62 and supporting head 68. Arm 74 may be pivotally attached to base 62 to impart a more compact profile for storage and transportation; a carrying strap 76 may also be attached to base 62 to facilitate transportation. With reference to FIG. 7, it can be seen that a reflective, polarizing filter 78 may be provided within base 62.
  • filter 78 contains a plurality of cholesteric filters 78a, 78b and 78c as may be required to cover the entire visible spectrum.
  • Filter 78 also includes another quarter-wave plate 30, and is surrounded by the same pair of Fresnel lenses 40 and 28.
  • the light source for OHP 60 includes lamp 44, reflector 46 and a condenser 80.
  • Filter 78 is preferably constructed as a drawer which may be slidably removed from base 62.
  • filter 78 may be located in an operative position when polarized light output is desirable (as when using an LCD panel on top of sheet 66), or filter 78 may be removed from the optical path if polarized light is not necessary (as when using overhead transparency sheets); it may not be necessary to remove filter 78 provided the projected visual image is no less acceptable to a normal viewer.
  • other features may be provided in OHP 60 which are outside the scope of the present invention, such as providing a folded optical path between the light source and stage area 64.
  • FIG. 7 results in an OHP having nearly 100% polarization efficiency, provided that a highly reflective surface (such as silver) is used on mirror 46, and interface losses are minimized as previously discussed.
  • a fairly open filament is preferred for lamp 44 so that most of the light reflected by filter 78 may bypass the filament to allow reflection by mirror 46.
  • An acceptable open filament capsule lamp having ANSI code EYB is available from Osram Corp. of Montgomery, N.Y. It may further be desirable to provide a quarter-wave plate 30 which is rotatable with respect to the polarizers in order to match the angle of polarization required by any LCD panel. In the case where OHP 60 is used with an LCD panel, the rear polarizer on the panel is redundant and may be removed for greater light transmission.
  • the foregoing invention may be modified to provide a reflective-type OHP, wherein the light source is located above the stage (in the projection head), and the stage itself consists of a reflective surface.
  • a (removable) cholesteric filter might be located in the projection head, between the lamp and the stage, to provide the high output, polarized light. This embodiment would also take advantage of light recycling by providing a reflector behind the lamp.
  • the cholesteric material might be chiral, and can further be a monomer or a polymer.
  • the most common cholesteric liquid crystals are aliphatic esters of cholesterol having a left-handed helix.
  • the material is polymeric, since the typical bandwidth for cholesteric liquid crystal monomers is about 50 nm, but that of polymers having cholesteric pendant groups is about 100 nm, provided they have the appropriate pitch and refractive anisotropy.
  • cholesteric polymers are much less temperature sensitive, and can also be cross-linked to make a solid film, eliminating the need for separate glass plates between the polarizer and adjacent components.
  • the preferred cholesteric composition is cholesteryl polysiloxane copolymer bound in a 4-membered ring.
  • Polarizers were formed by sheared alignment between glass plates, resulting in spectral widths of 100-150 nm. Peak wavelengths are selected by adjusting the ratio of the copolymers.
  • cholesteric polymers having a bandwidth of around 100 nm When cholesteric polymers having a bandwidth of around 100 nm are used, 3 layers can cover entire visible spectrum. Of course, the monomer polarizers could be used, but 6 layers would be required to cover the full visible spectrum. It will be appreciated that future improvements in cholesteric polarizer technology may result in a single layer being sufficient to cover the entire visible spectrum.
  • the present invention presents clear advantages over prior art LCD panels and LCD/OHP combinations.
  • the use of cholesteric polarizers imparts substantially improved color purity due to the sharp response curves and narrow bandwidths of the cholesteric filters, and further provides more illumination (brighter polarized output).
  • This invention also avoids problems relating to heat management found with absorptive polarizers, including color shifts and fading.

Abstract

A liquid crystal display (LCD) panel employs a cholesteric polarizer which passes light of a first circular polarization, but reflects light of a second circular polarization. The LCD panel may be monochrome or color; in the color embodiments, several different color filters are used, each having one or more cholesteric polarizers tuned to a specific bandwidth in the visible spectrum. These polarizers replace dyed (neutral or dichroic) polarizers of prior art LCD panels, and provide improved color purity. The invention may be enhanced by providing a light recycling scheme whereby the handedness of the circularly polarized light reflected by the polarizers is changed and redirected back to the polarizers. This recycling scheme may also be adapted to provide an overhead projector having a high output polarized light source, particularly useful in conjunction with an LCD panel.

Description

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to optical polarizers, and more particularly to a novel liquid crystal display panel and an overhead projector which incorporate tuned cholesteric polarizers.
2. Description of the Prior Art
Liquid crystal display (LCD) panels generally employ one of several different types of polarizers, including dyed stretched polymeric (neutral and dichroic), cholesteric or thin-film polarizers. For example, U.S. Pat. No. 4,917,465 discloses an LCD panel (depicted in FIG. 1) which uses both neutral polarizers 1 and dichroic polarizers 2 in a stacked arrangement. The dichroic dyes and associated liquid crystal layers 3 are selected to provide desired optical responses in order to yield the three primary subtractive colors, magenta, cyan and yellow.
One drawback to conventional dyed polarizers is that they are absorptive, i.e., polarization occurs due to different absorption coefficients for light polarized in different directions. This results in a loss of more than 50% of the available light, which adversely affects illumination in display systems using LCD's. Absorption of this amount of energy can also lead to heat management problems. In some projection systems using LCD's, such as overhead projectors (OHP's), illumination difficulties may be overcome by providing a brighter light source, such as a metal halide lamp; this solution, however, is expensive, and typically exacerbates heat management problems, and further introduces a serious safety hazard.
Another drawback to dichroic dyed polarizers is that their spectral cutoffs are limited by the dyes themselves. In many uses, such as stacked, color supertwisted nematic (STN) LCD panels, these cutoffs are not as sharp as would be desired, and their use results in less than ideal color purity and brightness or, alternatively, necessitates use of neutral polarizers instead.
Cholesteric polarizers have sharper spectral cutoffs which can be employed to improve these uses, and are reflective rather than absorptive but, prior to the present invention, cholesteric polarizers have not been incorporated into flat panel LCD designs. These polarizers utilize liquid crystal material in which the elongated molecules are parallel to each other within the plane of a layer, but the direction of orientation twists slightly from layer to layer to form a helix through the thickness of the polarizer. Cholesteric polarizers are either right- or left-handed and, depending upon this handedness, transmit or reflect circularly polarized light in a narrow optical bandwidth. As suggested by Schadt et al. (see SID 1990 Symposium Digest pp. 324-326; and 29 Jap. J.Appl.Phys. pp. L634-L637 and pp. 1974-1984), the reflective properties of cholesteric filters may be exploited to recycle the reflected light. See also Maurer et al. (SID 1990 Symposium Digest pp. 110-113, and 1991 Record of the International Display Research Conference, pp. 57-59). Unfortunately, these devices are incompatible with the configuration of a flat LCD panel, such as is used in either direct view or with an OHP since, for example, their wide-aperture case does not generate highly polarized light; other of the devices are particularly unsuitable in stacked LCD designs.
In U.S. Pat. No. 4,987,410, cholesteric polarizers are used to selectively block one of two images in a head-up/head-down display. While that patent further discloses the use of multiple polarizers to selectively block discrete color images, the polarizers are never used for manipulating the color tone of a single image. The configuration of the '410 device is also generally incompatible with that of an LCD panel. See additionally U.S. Pat. No. 5,050,966. It would, therefore, be desirable and advantageous to devise an LCD panel which incorporates cholesteric polarizers, but provides high efficiency, wide aperture transmission of the light for stacked LCD panel designs. It would be further advantageous if such a wide aperture polarized light source could be directly incorporated into an OHP to accommodate any type of LCD panel (e.g., color or monochrome). Finally, the systems would preferably impart greater brightness, and be usable over a wider range of operating temperatures.
SUMMARY OF THE INVENTION
The foregoing objectives are achieved in a stacked liquid crystal display panel having a plurality of cholesteric polarizers forming color and neutral filters, interposed between supertwisted, nematic (STN) liquid crystal cells. Quarter-wave plates are used to convert the circularly polarized light into linearly polarized light before entry into the STN layers. Fresnel lenses are used to collimate and condense the light, increasing the efficiency of the panel. If a subtractive scheme is used to blend colors from the three STN layers, the color cholesteric filters will correspond to two primary subtractive colors; this means that each filter will include one or more polarizers tuned to the bandwidth of a single primary additive color. Conversely, if an additive scheme is used, each filter will correspond to a primary additive color; this means that each filter will include two or more polarizers tuned to two bandwidths of the complementary primary additive colors. In an alternative embodiment, no neutral polarizers are used.
The cholesteric polarizers of the present invention may also be incorporated into an overhead projector to yield a high output polarized light source. A plurality of polarizers are selected, according to their bandwidths, to cover the entire visible spectrum, and are combined with a single quarter-wave plate and two Fresnel lenses. When this structure is incorporated into the base of an OHP, a light source which includes a back reflector may be used to recycle that portion of light reflected by the polarizers.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features of the invention are set forth in the appended claims. The invention itself, however, will best be understood by reference to the accompanying drawings, wherein:
FIG. 1 is an exploded perspective view of a prior art, color, stacked STN LCD panel using neutral and dichroic polaroid polarizers;
FIG. 2 is a schematic side view of one embodiment of the color LCD panel of the present invention, using cholesteric color and neutral filters;
FIG. 3 is a schematic side view of another embodiment of the color LCD panel of the present invention, using no neutral filters;
FIG. 4 is a schematic side view of still another embodiment of the color LCD panel of the present invention, in which the first filter polarizes light in the entire visible spectrum;
FIG. 5 is a schematic side view of yet another embodiment of the color LCD panel of the present invention, utilizing an additive color scheme;
FIG. 6 is a perspective view of one embodiment of the high output polarized light overhead projector of the present invention; and
FIG. 7 is a schematic side view of the cholesteric filter and light source located in the overhead projector of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the figures, and in particular with reference to FIG. 2, there is depicted one embodiment 10 of the liquid crystal display (LCD) panel of the present invention. LCD panel 10 generally comprises a plurality of reflective polarizing filters 12, 14, 16 and 18, a plurality of liquid crystal cells 20, 22 and 24, and two Fresnel lenses 26 and 28. Lens 26 is used to collect and collimate the light for the stacked arrangement, while lens 28 is used to condense the light toward other optical components (such as the projector head of the overhead projector described in FIG. 6). Each of the filters includes one or more quarter-wave plates 30, and at least one cholesteric circular polarizer. For example, in the embodiment of FIG. 2, which utilizes a subtractive color scheme similar to the prior art device of FIG. 1, filter 12 preferably includes a single cholesteric polarizer 12a which is tuned to red wavelengths (i.e., an approximate bandwidth of 600 nm to 700 nm). Such a cholesteric polarizer will pass all green and blue hues, but will pass only one polarization component of red. The component to be passed depends upon the handedness of the cholesteric molecules in polarizer 12a. If those molecules are right-handed, then right-handed (RH) circularly polarized (CP) light will be reflected, but left-handed (LH) CP light will be transmitted. Transmission and reflection of these components is nearly 100% efficient. Although the handedness of the cholesteric material does not matter, the inventors are presently using material which is left-handed (discussed further below).
In order to use a subtractive color scheme, it is necessary to provide filters for the three primary subtractive colors, cyan, yellow and magenta. In the present invention, this is accomplished by combining the tuned cholesteric filters with correspondingly tuned liquid crystal cells. In LCD panel 10, filter 12 is combined with cell 20 to create a cyan filter. As explained above, red light passing through polarizer 12a is split into two circularly polarized components, with only one of those components passing through polarizer 12a. The first quarter-wave plate 30 then converts this circularly polarized light into linearly polarized light so that it may be further regulated by cell 20. Cell 20 is tuned to select or deselect (reject) passage of this red light by modulating the phase of the linearly polarized light (rotating the angle of polarization), as discussed in U.S. Pat. No. 4,917,465 (see FIG. 9 of that patent), which is hereby incorporated. Tuning is accomplished by choosing an appropriate thickness for the liquid crystal layer of cell 20, and by choosing a material which has an appropriate optical anisotropy. The preferred material is a supertwisted nematic (STN) liquid crystal. The cells have individually addressable pixels as known in the art.
Filter 14 is neutral and includes three separate cholesteric polarizers 14a, 14b and 14c which are tuned, respectively, to the three primary colors red, green and blue. A first quarter-wave plate 30 in filter 14 is used to convert the linear polarized light to circular polarized light, and a second quarter-wave plate 30 in filter 14 is used to convert the circular polarized light into linear polarized light. Blue light passing through filter 14 is selected or deselected by yellow cell 22. Since all light outside of each polarizer's bandwidth completely passes through the polarizer, several such polarizers can be stacked in series without affecting the optical performance of each. In this regard, it is understood that separate polarizers are needed for a neutral filter in order to cover the entire visible spectrum. As discussed further below, more than three polarizers may be needed if the bandwidths are particularly narrow or, conversely, it is conceivable that a single polarizer could be devised which would have a sufficiently large bandwidth to cover the visible spectrum.
Filter 16 is essentially identical to filter 14, and includes three cholesteric polarizers 16a, 16b and 16c which are also tuned, respectively, to the three primary colors red, green and blue. Green light passing through filter 14 is selected/deselected by magenta cell 24. Another pair of quarter-wave plates 30 are used as in filter 14. Filter 18, which includes a single cholesteric polarizer 18a tuned to green, and another quarter-wave plate 30 interposed between polarizer 18a and cell 24, acts as an analyzer to render the modulation pattern in the outgoing light visible.
Those skilled in the art will appreciate the significant concern of light loss due to reflections at the multiple air-glass interfaces between the various components in LCD panel 10. These losses can be minimized by sharing glass substrates to form adjacent layers between the components, by using anti-reflection coatings at air interfaces, by using index-matching adhesives and laminations in place of air gaps, or any combination of these techniques.
Referring now to FIG. 3, that figure depicts another embodiment 32 of an LCD panel made according to the present invention. Panel 32 includes the same rear (cyan) and front (magenta) filters 12 and 18, but neutral filters 14 and 16 have been replaced, respectively, with green and red filters 34 and 36. Filter 34 includes two cholesteric polarizers 34a and 34b tuned, respectively, to red and blue, while filter 36 includes two cholesteric polarizers 36a and 36b tuned, respectively, to green and blue. Both filters use two quarter-wave plates each, and the same cells 20, 22 and 24 may be used in panel 32. This embodiment is considered most preferable since panel 32 combines high quality color polarizers with the greatest light transmission possible in a stacked, color STN LCD panel.
Yet another embodiment 38 of an alternative LCD panel is shown in FIG. 4. This embodiment is essentially identical to panel 32 except for the use of a different rear Fresnel lens 40 and a different first filter 42. Panel 38 is designed to take advantage of the reflective properties of cholesteric polarizers, and is particularly useful in display systems having a point light source 44, such as an overhead projector. Accordingly, Fresnel lens 40 should be a convergent lens. Filter 42 is neutral, in order to allow for recycling of that portion of the light which is reflected by the polarizers 42a, 42b and 42c. This reflected light may be recycled by providing a mirror 46 or other reflective surface proximate to light source 44. In this manner, the light which is reflected by the polarizers is redirected (by lens 40) toward mirror 46; light reflected by polarizers 42b and 42c passes back downwardly through the other polarizers without affecting the reflected light. When the light is reflected in mirror 46, it changes the handedness of the circular polarization. Thus the recycled light is now of the proper handedness to pass through filter 42.
Circular, cholesteric polarizers may also be used to improve the performance (color purity) of other multilayer color LCD panels, such as those depicted in U.S. Pat. Nos. 4,416,514 and 4,838,655. For example, cholesteric polarizers may be used to create an additive LCD panel 48, as illustrated in FIG. 5. This panel is also very similar to the foregoing panels in that it employs the same LCD cells 20, 22 and 24, a plurality of quarter-wave plates 30, and a pair of Fresnel lenses 26 and 28. It also uses the same intermediate filters 34 and 36, but the first filter 50 is now a blue filter, having two cholesteric polarizers 50a and 50b tuned to red and green, respectively. FIG. 5 also serves to illustrate how the analyzer 52 in any of the foregoing embodiments may be a neutral (stretch polymeric) polarizer rather than a cholesteric polarizer combined with a quarter-wave plate. It is understood that the order of the filters (as well as the order of the component polarizers in each filter) may vary without affecting the panel's output. It is also understood that cholesteric polarizers can replace one, several, or all of the dyed dichroic and neutral polarizers of the prior art panels. It is further understood that the present invention could be applied to hybrid additive color LCD systems, such as the guest-host twisted nematic (TN) system of U.S. Pat. No. 4,838,655. The LCD cells to be used should rotate linear polarized light between 90° (when off) and 0° (when fully on), and may be chosen from TN, ferroelectric, or other LCD types.
Those skilled in the art will appreciate that other variations of the disclosed embodiments may be devised, including an embodiment (not shown) that eliminates the need for the quarter-wave plates by providing LCD cells which modulate circular polarized light. Such cells include TN cells that act as a half wave retarder, instead of the conventional TN waveguiding mode, and electrically-controlled birefringent ECB LCD's, also known as DAP LCD's (deformed vertically-aligned phase).
Turning now to FIG. 6, the recycling concept of FIG. 4 may also be applied to an overhead projector (OHP) 60. OHP 60 includes many conventional parts, such as a base 62 having a stage area 64 (typically a glass sheet 66), a projector head 68 having a projection lens 70 and mirror 72, and an arm 74 attached to base 62 and supporting head 68. Arm 74 may be pivotally attached to base 62 to impart a more compact profile for storage and transportation; a carrying strap 76 may also be attached to base 62 to facilitate transportation. With reference to FIG. 7, it can be seen that a reflective, polarizing filter 78 may be provided within base 62. As with filter 42, filter 78 contains a plurality of cholesteric filters 78a, 78b and 78c as may be required to cover the entire visible spectrum. Filter 78 also includes another quarter-wave plate 30, and is surrounded by the same pair of Fresnel lenses 40 and 28. The light source for OHP 60 includes lamp 44, reflector 46 and a condenser 80. Filter 78 is preferably constructed as a drawer which may be slidably removed from base 62. In this manner, filter 78 may be located in an operative position when polarized light output is desirable (as when using an LCD panel on top of sheet 66), or filter 78 may be removed from the optical path if polarized light is not necessary (as when using overhead transparency sheets); it may not be necessary to remove filter 78 provided the projected visual image is no less acceptable to a normal viewer. Of course, other features may be provided in OHP 60 which are outside the scope of the present invention, such as providing a folded optical path between the light source and stage area 64.
The construction of FIG. 7 results in an OHP having nearly 100% polarization efficiency, provided that a highly reflective surface (such as silver) is used on mirror 46, and interface losses are minimized as previously discussed. A fairly open filament is preferred for lamp 44 so that most of the light reflected by filter 78 may bypass the filament to allow reflection by mirror 46. An acceptable open filament capsule lamp having ANSI code EYB is available from Osram Corp. of Montgomery, N.Y. It may further be desirable to provide a quarter-wave plate 30 which is rotatable with respect to the polarizers in order to match the angle of polarization required by any LCD panel. In the case where OHP 60 is used with an LCD panel, the rear polarizer on the panel is redundant and may be removed for greater light transmission.
The foregoing invention may be modified to provide a reflective-type OHP, wherein the light source is located above the stage (in the projection head), and the stage itself consists of a reflective surface. In this embodiment, a (removable) cholesteric filter might be located in the projection head, between the lamp and the stage, to provide the high output, polarized light. This embodiment would also take advantage of light recycling by providing a reflector behind the lamp.
Several different materials may be used in the cholesteric polarizers of the present invention. The cholesteric material might be chiral, and can further be a monomer or a polymer. The most common cholesteric liquid crystals are aliphatic esters of cholesterol having a left-handed helix. In the preferred embodiment, the material is polymeric, since the typical bandwidth for cholesteric liquid crystal monomers is about 50 nm, but that of polymers having cholesteric pendant groups is about 100 nm, provided they have the appropriate pitch and refractive anisotropy. Besides having a broader spectral range, cholesteric polymers are much less temperature sensitive, and can also be cross-linked to make a solid film, eliminating the need for separate glass plates between the polarizer and adjacent components. The preferred cholesteric composition is cholesteryl polysiloxane copolymer bound in a 4-membered ring. Polarizers were formed by sheared alignment between glass plates, resulting in spectral widths of 100-150 nm. Peak wavelengths are selected by adjusting the ratio of the copolymers.
When cholesteric polymers having a bandwidth of around 100 nm are used, 3 layers can cover entire visible spectrum. Of course, the monomer polarizers could be used, but 6 layers would be required to cover the full visible spectrum. It will be appreciated that future improvements in cholesteric polarizer technology may result in a single layer being sufficient to cover the entire visible spectrum.
The present invention presents clear advantages over prior art LCD panels and LCD/OHP combinations. The use of cholesteric polarizers imparts substantially improved color purity due to the sharp response curves and narrow bandwidths of the cholesteric filters, and further provides more illumination (brighter polarized output). This invention also avoids problems relating to heat management found with absorptive polarizers, including color shifts and fading.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as alternative embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. For example, the present invention could also be used with laptop computer LCD displays, or large-screen LCD televisions. Also, a wider variation in color tones could be provided by using more filter/cell pairs tuned to narrower bandwidths. It is therefore contemplated that the appended claims will cover such modifications that fall within the true scope of the invention.

Claims (17)

I claim:
1. A display device adapted to display color images, comprising:
first, second and third circular polarizers which pass circularly polarized light in a bandwidth within the visible spectrum, each of said polarizers being generally planar;
first, second, third, fourth and fifth quarter-wave plates for converting circularly polarized light into linearly polarized light, each of said quarter-wave plates being generally planar;
first, second and third addressable, liquid crystal cells for selectively modulating the phase of linearly polarized light;
lens means for collecting and collimating light;
said first circular polarizer being interposed between said lens means and said first liquid crystal cell, and tuned to circularly polarize light of a first primary color;
said first quarter-wave plate being interposed between said first circular polarizer and said first liquid crystal cell;
said first liquid crystal cell being tuned to selectively rotate linearly polarized light of said first primary color;
said second circular polarizer being interposed between said first and second liquid crystal cells, and tuned to circularly polarize light of all three primary colors;
said second quarter-wave plate being interposed between said second circular polarizer and said first liquid crystal cell;
said third quarter-wave plate being interposed between said second circular polarizer and said second liquid crystal cell;
said second liquid crystal cell being tuned to selectively rotate linearly polarized light of a second primary color;
said third circular polarizer being interposed between said second and third liquid crystal cells, and tuned to circularly polarize light of all three primary colors;
said fourth quarter-wave plate being interposed between said third circular polarizer and said second liquid crystal cell;
said fifth quarter-wave plate being interposed between said third circular polarizer and said third liquid crystal cell;
said third liquid crystal cell being tuned to selectively rotate linearly polarized light of a third primary color; and
analyzer means for rendering visible modulated light exiting said third liquid crystal cell.
2. The display device of claim 1 further comprising second lens means, adjacent said analyzer means, opposite from said fifth quarter-wave plate, for condensing light which passes through said analyzer means.
3. The display device of claim 1 wherein at least one of said polarizers:
passes light in said bandwidth which is circularly polarized with a first right/left handedness; and
reflects light in said bandwidth which is circularly polarized with a second right/left handedness.
4. The display device of claim 1 wherein at least one of said polarizers comprises a cholesteric polarizer tuned to said bandwidth.
5. A display device adapted to display color images, comprising:
first, second and third circular polarizers which pass circularly polarized light in a bandwidth within the visible spectrum, each of said polarizers being generally planar;
first, second and third addressable, liquid crystal cells for selectively modulating the phase of linearly polarized light;
first, second, third, fourth and fifth quarter-wave plates for converting circularly polarized light into linearly polarized light, each of said quarter-wave plates being generally planar;
lens means for collecting and collimating light;
said first circular polarizer being interposed between said lens means and said first liquid crystal cell, and tuned to circularly polarize light of a first primary color;
said first quarter-wave plate being interposed between said first circular polarizer and said first liquid crystal cell;
said first liquid crystal cell being tuned to selectively rotate linearly polarized light of said first primary color;
said second circular polarizer being interposed between said first and second liquid crystal cells, and tuned to circularly polarize light of said first primary color and of a second primary color;
said second quarter-wave plate being interposed between said second circular polarizer and said first liquid crystal cell;
said third quarter-wave plate being interposed between said second circular polarizer and said second liquid crystal cell;
said second liquid crystal cell being tuned to selectively rotate linearly polarized light of said second primary color;
said third circular polarizer being interposed between said second and third liquid crystal cells, and tuned to circularly polarize light of said second primary color and of a third primary color;
said fourth quarter-wave plate being interposed between said third circular polarizer and said second liquid crystal cell;
said fifth quarter-wave plate being interposed between said third circular polarizer and said third liquid crystal cell;
said third liquid crystal cell being tuned to selectively rotate linearly polarized light of said third primary color; and
analyzer means for rendering visible modulated light exiting said third liquid crystal cell.
6. The display device of claim 5 further comprising second lens means, adjacent said analyzer means, opposite from said fifth quarter-wave plate, for condensing light which passes through said analyzer means.
7. The display device of claim 5 wherein at least one of said polarizers:
passes light in said bandwidth which is circularly polarized with a first right/left handedness; and
reflects light in said bandwidth which is circularly polarized with a second right/left handedness.
8. The display device of claim 7 further comprising:
a fourth circular polarizer adjacent to said first circular polarizer, tuned to circularly polarize light of said second and third primary colors;
a light source at a known effective distance from the display device; and
a back reflector for said light source;
wherein said lens means comprises a convergent Fresnel lens having a focal length which is approximately equal to said effective distance.
9. The display device of claim 5 wherein at least one of said polarizers comprises a cholesteric polarizer tuned to said bandwidth.
10. A display device adapted to display color images, comprising:
first, second and third circular polarizers for passing circularly polarized light in a bandwidth within the visible spectrum, each of said polarizers being generally planar;
first, second and third addressable, liquid crystal cells for selectively modulating the phase of linearly polarized light;
first, second, third, fourth and fifth quarter-wave plates for converting circularly polarized light into linearly polarized light, each of said quarter-wave plates being generally planar;
lens means for collecting and collimating light;
said first circular polarizer being interposed between said lens means and said first liquid crystal cell, and tuned to circularly polarize light of a first primary color and a second primary color;
said first quarter-wave plate being interposed between said first circular polarizer and said first liquid crystal cell;
said first liquid crystal cell being tuned to selectively rotate linearly polarized light of said first primary color;
said second circular polarizer being interposed between said first and second liquid crystal cells, and tuned to circularly polarize light of said first primary color and of a third primary color;
said second quarter-wave plate being interposed between said second circular polarizer and said first liquid crystal cell;
said third quarter-wave plate being interposed between said second circular polarizer and said second liquid crystal cell;
said second liquid crystal cell being tuned to selectively rotate linearly polarized light of said second primary color;
said third circular polarizer being interposed between said second and third liquid crystal cells, and tuned to circularly polarize light of said second and third primary colors;
said fourth quarter-wave plate being interposed between said third circular polarizer and said second liquid crystal cell;
said fifth quarter-wave plate being interposed between said third circular polarizer and said third liquid crystal cell;
said third liquid crystal cell being tuned to selectively rotate linearly polarized light of said third primary color; and
analyzer means for rendering visible modulated light exiting said third liquid crystal cell.
11. The display device of claim 10 further comprising second lens means, adjacent said analyzer means, opposite from said fifth quarter-wave plate, for condensing light which passes through said analyzer means.
12. The display device of claim 10 wherein at least one of said polarizers:
passes light in said bandwidth which is circularly polarized with a first right/left handedness; and
reflects light in said bandwidth which is circularly polarized with a second right/left handedness.
13. The display device of claim 10 wherein at least one of said polarizers comprises a cholesteric polarizer tuned to said bandwidth.
14. An overhead projector having high output polarized light, comprising:
a base having a stage area;
a projector head mounted to said base, proximate said stage area;
a light source in said base;
means for directing light from said light source to said stage area, defining an optical path;
means for reflecting light, said light reflecting means located adjacent said light source and opposite said stage area with respect to said optical path;
first lens means for collecting and collimating light from said light source toward said stage area;
second lens means, interposed between said first lens means and said stage area, for condensing light from said first lens means and directing it through said stage area toward said projector head;
polarizer means, located between said first and second lens means, for passing light of a first polarization, and for reflecting light of a second polarization; and
means for removing said polarizer means from said base.
15. The overhead projector of claim 14 wherein said polarizer means comprises at least one circular polarizer which passes light that is circularly polarized with a first right/left handedness, and reflects light that is circularly polarized with a second right/left handedness.
16. The overhead projector of claim 14 further comprising a quarter-wave plate interposed between said polarizer means and said second lens means.
17. The overhead projector of claim 14 wherein said removing means comprises a drawer which is slidably attached to said base, said polarizer means being located in said drawer.
US07/999,230 1992-12-31 1992-12-31 Cholesteric polarizer for liquid crystal display and overhead projector Expired - Fee Related US5325218A (en)

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EP94903583A EP0677178B1 (en) 1992-12-31 1993-12-09 Cholesteric polarizer for liquid crystal display and overhead projector
KR1019950702688A KR960700458A (en) 1992-12-31 1993-12-09 CHOLESTERIC POLARIZER FOR LIQUID CRYSTAL DISPLAY AND OVERHEAD PROJECTOR
JP6516003A JPH08505480A (en) 1992-12-31 1993-12-09 Cholesteric polarizers for liquid crystal displays and overhead projectors
PCT/US1993/012034 WO1994016355A1 (en) 1992-12-31 1993-12-09 Cholesteric polarizer for liquid crystal display and overhead projector
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Cited By (144)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5408346A (en) * 1993-10-20 1995-04-18 Kaiser Electro-Optics, Inc. Optical collimating device employing cholesteric liquid crystal and a non-transmissive reflector
WO1995020180A1 (en) * 1994-01-25 1995-07-27 Fergason James L Display system and method
WO1995029427A1 (en) * 1994-04-21 1995-11-02 Reveo, Inc. Transportable computer systems having dual viewing modes
US5514127A (en) * 1993-02-18 1996-05-07 Central Research Laboratories Limited Apparatus for irradiating an area with a controllable pattern of light
EP0713126A1 (en) * 1994-11-14 1996-05-22 F. Hoffmann-La Roche Ag Coloured display with electrically controllable liquid crystal filters disposed in series
EP0718645A2 (en) * 1994-12-19 1996-06-26 Sharp Kabushiki Kaisha Optical device and head-mounted display using said optical device
US5532852A (en) * 1994-02-23 1996-07-02 Kaiser Aerospace And Electronics Corporation High speed, high ambient viewability liquid crystal display assembly
US5532854A (en) * 1994-01-25 1996-07-02 Fergason; James L. Folded variable birefringerence zeroth order hybrid aligned liquid crystal apparatus
US5537233A (en) * 1993-11-25 1996-07-16 Sanyo Electric Co., Ltd. Direct-vision/projection type liquid-crystal display having light source at the edge of a gap between two liquid crystal panels
US5541745A (en) * 1994-01-25 1996-07-30 Fergason; James L. Illumination system for a display using cholesteric liquid crystal reflectors
US5548422A (en) * 1993-06-28 1996-08-20 In Focus Systems, Inc. Notch filters with cholesteric polarizers with birefringent film and linear polarizer
US5555114A (en) * 1992-11-30 1996-09-10 Sanyo Electric Co., Ltd. Liquid crystal display with reflective color filters
US5570210A (en) * 1993-05-06 1996-10-29 Fujitsu Limited Liquid crystal display device with directional backlight and image production capability in the light scattering mode
WO1997020250A1 (en) * 1995-11-28 1997-06-05 Reveo, Inc. Image display systems having direct and projection viewing modes
US5686979A (en) * 1995-06-26 1997-11-11 Minnesota Mining And Manufacturing Company Optical panel capable of switching between reflective and transmissive states
US5692226A (en) * 1994-09-28 1997-11-25 Hall; Dennis R. Stereoscopic recording systems utilizing chiral liquid crystals
US5712694A (en) * 1994-09-16 1998-01-27 Kabushiki Kaisha Toshiba LCD comprising a light separating element including a cholesteric liquid crystal sheet
US5717422A (en) * 1994-01-25 1998-02-10 Fergason; James L. Variable intensity high contrast passive display
US5721603A (en) * 1993-01-11 1998-02-24 U.S. Philips Corporation Illumination system and display device including such a system
WO1998011275A1 (en) * 1996-09-16 1998-03-19 Reveo, Inc. High-brightness color liquid crystal display panel employing systemic light recycling
US5751385A (en) * 1994-06-07 1998-05-12 Honeywell, Inc. Subtractive color LCD utilizing circular notch polarizers and including a triband or broadband filter tuned light source or dichroic sheet color polarizers
US5793456A (en) * 1993-01-11 1998-08-11 U.S. Philips Corporation Cholesteric polarizer and the manufacture thereof
US5799231A (en) * 1996-07-25 1998-08-25 International Business Machines Corporation Variable index distributed mirror
US5801793A (en) * 1994-04-21 1998-09-01 Reveo, Inc. Backlighting construction for use in computer-based display systems having direct and projection viewing modes of operation
US5808713A (en) * 1995-09-22 1998-09-15 U.S. Philips Corporation Flat-panel picture display device
US5818615A (en) * 1993-12-02 1998-10-06 Ois Optical Imaging Systems, Inc. Liquid crystal display with patterned retardation films
US5822029A (en) * 1994-12-29 1998-10-13 Sharp Kabushiki Kaisha Illumination system and display device
US5825542A (en) * 1995-06-26 1998-10-20 Minnesota Mining And Manufacturing Company Diffusely reflecting multilayer polarizers and mirrors
US5828488A (en) 1993-12-21 1998-10-27 Minnesota Mining And Manufacturing Co. Reflective polarizer display
US5831375A (en) * 1995-08-11 1998-11-03 Minnesota Mining And Manufacturing Company Electroluminescent lamp using multilayer optical film
US5835166A (en) * 1994-08-17 1998-11-10 Hall; Dennis R. Chiral nematic liquid crystal polarization modulated color display for stereoscopic viewing device
US5841494A (en) * 1996-06-26 1998-11-24 Hall; Dennis R. Transflective LCD utilizing chiral liquid crystal filter/mirrors
US5856855A (en) * 1995-08-23 1999-01-05 U.S. Philips Corporation Edge-lit illumination system containing cholesteric polarizer and diffuser behind waveguide
EP0895116A2 (en) * 1997-07-31 1999-02-03 Compaq Computer Corporation Liquid crystal color shutters using reflective polarizer
US5940150A (en) * 1991-11-27 1999-08-17 Reveo, Inc. Electro-optical glazing structures having total-reflection and transparent modes of operation for use in dynamical control of electromagnetic radiation
US5940152A (en) * 1997-05-01 1999-08-17 Wilson; Stephen S. Dual-fresnel field lens for a single-panel LCD projection system
US5946431A (en) * 1993-07-30 1999-08-31 Molecular Dynamics Multi-functional photometer with movable linkage for routing light-transmitting paths using reflective surfaces
US6025897A (en) 1993-12-21 2000-02-15 3M Innovative Properties Co. Display with reflective polarizer and randomizing cavity
US6034752A (en) * 1997-03-22 2000-03-07 Kent Displays Incorporated Display device reflecting visible and infrared radiation
US6075651A (en) * 1999-01-28 2000-06-13 Kaiser Electro-Optics, Inc. Compact collimating apparatus
US6078363A (en) * 1996-11-11 2000-06-20 Sharp Kabushiki Kaisha Image display apparatus
US6088067A (en) * 1995-06-26 2000-07-11 3M Innovative Properties Company Liquid crystal display projection system using multilayer optical film polarizers
US6096375A (en) 1993-12-21 2000-08-01 3M Innovative Properties Company Optical polarizer
US6104456A (en) * 1996-04-18 2000-08-15 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Liquid crystal display using circular polarized light and light emitting screen
US6108131A (en) * 1998-05-14 2000-08-22 Moxtek Polarizer apparatus for producing a generally polarized beam of light
US6111700A (en) * 1996-09-05 2000-08-29 Fujitsu Limited Optical display device having a reflection-type polarizer
US6118504A (en) * 1996-08-23 2000-09-12 Seiko Epson Corporation Display device and electronic apparatus comprising the same
US6118507A (en) * 1998-04-20 2000-09-12 Sony Corporation Reflection TN-ECB having particular relationships between perpendicular axis and oriented directions
US6122103A (en) * 1999-06-22 2000-09-19 Moxtech Broadband wire grid polarizer for the visible spectrum
US6124971A (en) * 1995-06-26 2000-09-26 3M Innovative Properties Company Transflective displays with reflective polarizing transflector
US6130734A (en) * 1996-06-14 2000-10-10 Seiko Instruments Inc. Color LCD having particular parameters for LC layer, retarder, color polarizer align layer
US6141069A (en) * 1994-07-27 2000-10-31 University Technology Corporation Liquid crystal phase modulator using a ferroelectric liquid crystal with a rotatable axis and cholesteric circular polarizers
US6160597A (en) * 1993-02-17 2000-12-12 Rolic Ag Optical component and method of manufacture
US6160663A (en) * 1998-10-01 2000-12-12 3M Innovative Properties Company Film confined to a frame having relative anisotropic expansion characteristics
US6208463B1 (en) 1998-05-14 2001-03-27 Moxtek Polarizer apparatus for producing a generally polarized beam of light
WO2001023919A1 (en) * 1999-09-29 2001-04-05 Fujitsu General Limited Polarized light color filter and video projector comprising the same
WO2001025841A1 (en) * 1999-10-01 2001-04-12 Citizen Watch Co., Ltd. Liquid crystal display panel and electronic apparatus using it
US6234634B1 (en) 1999-07-28 2001-05-22 Moxtek Image projection system with a polarizing beam splitter
US6243199B1 (en) 1999-09-07 2001-06-05 Moxtek Broad band wire grid polarizing beam splitter for use in the visible wavelength region
US6264336B1 (en) 1999-10-22 2001-07-24 3M Innovative Properties Company Display apparatus with corrosion-resistant light directing film
US6288840B1 (en) 1999-06-22 2001-09-11 Moxtek Imbedded wire grid polarizer for the visible spectrum
US20010036013A1 (en) * 1999-04-22 2001-11-01 3M Innovative Properties Company Optical devices using reflecting polarizing materials
US6377325B2 (en) * 1997-07-09 2002-04-23 Sadeg M. Faris Reflective film material having symmetrical reflection characteristics and method and apparatus for making the same
EP1203980A1 (en) * 2000-11-03 2002-05-08 Rolic AG Switchable color filter
US6404464B1 (en) 1995-10-30 2002-06-11 Reveo, Inc. Method and system for producing color images with improved brightness and color characteristics on radiation absorptive surfaces
US20020075434A1 (en) * 2000-06-26 2002-06-20 Yingqiu Jiang Cholesteric liquid crystal polarizing device
US6414728B1 (en) 1994-04-21 2002-07-02 Reveo, Inc. Image display system having direct and projection viewing modes
US6417903B1 (en) * 1997-06-30 2002-07-09 Citizen Watch Co., Ltd. Liquid crystal display device
US6447120B2 (en) 1999-07-28 2002-09-10 Moxtex Image projection system with a polarizing beam splitter
US20020141194A1 (en) * 1995-06-26 2002-10-03 3M Innovative Properties Company Backlight system with multilayer optical film reflector
US6532048B1 (en) * 1999-02-01 2003-03-11 Seiko Epson Corporation Display device and electronic device using the same
US20030058387A1 (en) * 2000-02-03 2003-03-27 Jurg Fuenfschilling Colour switch
US6559911B2 (en) * 1997-02-18 2003-05-06 Dai Nippon Printing Co., Ltd. Polarization light splitting film, backlight system and liquid crystal display having particular diffusion layer under optical rotation selection layer
US6559903B2 (en) 1991-11-27 2003-05-06 Reveo, Inc. Non-absorptive electro-optical glazing structure employing composite infrared reflective polarizing filter
WO2003040819A1 (en) * 2001-11-09 2003-05-15 Koninklijke Philips Electronics N.V. Fast fast liquid crystal display system with high contrast
US6573961B2 (en) 1994-06-27 2003-06-03 Reveo, Inc. High-brightness color liquid crystal display panel employing light recycling therein
US6612702B1 (en) * 1998-02-16 2003-09-02 Seiko Corporation Projection display device
US6626545B2 (en) 1999-10-22 2003-09-30 3M Innovative Properties Co Light directing construction having corrosion resistant feature
US6633354B2 (en) 1991-11-27 2003-10-14 Reveo, Inc. Spectrum-controllable reflective polarizers having electrically-switchable modes of operation
US6646710B2 (en) * 2000-04-27 2003-11-11 Fuji Xerox Co., Ltd. Light modulator
US6667794B2 (en) * 2000-09-25 2003-12-23 Fuji Photo Film Co., Ltd. Collimator utilizing wavelength selective reflection and backlight system
US6666556B2 (en) 1999-07-28 2003-12-23 Moxtek, Inc Image projection system with a polarizing beam splitter
US6671008B1 (en) 1991-11-27 2003-12-30 Reveo, Inc. Electro-optical glazing structures having scattering and transparent modes of operation and methods and apparatus for making the same
US6729730B2 (en) 2000-02-04 2004-05-04 Seiko Epson Corporation Projector
US6738114B1 (en) 1996-11-04 2004-05-18 Reveo, Inc. Liquid crystal film structures with phase-retardation surface regions formed therein
US6753044B2 (en) 1991-11-27 2004-06-22 Reveo, Inc. Coloring media having improved brightness and color characteristics
US20040125449A1 (en) * 2002-12-30 2004-07-01 Sales Tasso R. Grid polarizer with suppressed reflectivity
US20040135742A1 (en) * 2002-12-31 2004-07-15 Weber Michael F. Head-up display with polarized light source and wide-angle p-polarization reflective polarizer
US20040141120A1 (en) * 1997-02-26 2004-07-22 Faris Sadeg M. Variable optical attenuator based on electrically switchable cholesteric liquid crystal reflective polarizers
US6785050B2 (en) 2002-05-09 2004-08-31 Moxtek, Inc. Corrosion resistant wire-grid polarizer and method of fabrication
US6804058B1 (en) 1993-12-21 2004-10-12 3M Innovative Properties Company Electroluminescent light source and display incorporating same
US20040246405A1 (en) * 1997-11-04 2004-12-09 Faris Sadeg M. Liquid crystal film structures with phase-retardation surface regions formed therein
US20050007514A1 (en) * 1994-04-21 2005-01-13 Faris Sadeg M. Backlighting construction for use in computer-based display systems having direct and projection viewing modes of operation
US6882384B1 (en) * 1995-05-23 2005-04-19 Colorlink, Inc. Color filters and sequencers using color selective light modulators
US20050093796A1 (en) * 1994-10-25 2005-05-05 Fergason James L. Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US20050104027A1 (en) * 2003-10-17 2005-05-19 Lazarev Pavel I. Three-dimensional integrated circuit with integrated heat sinks
US6897936B1 (en) 1999-04-06 2005-05-24 Inventqjaya Sdn. Bhd Electro-optical glazing structures having scattering and transparent modes of operation
US20060066803A1 (en) * 2004-09-30 2006-03-30 Aylward Peter T Substrate free flexible liquid crystal displays
US20060119937A1 (en) * 2004-12-06 2006-06-08 Moxtek, Inc. Multilayer wire-grid polarizer
US20060187382A1 (en) * 2002-10-31 2006-08-24 Kim Gi-Hong Liquid crystal display device using cholesteric liquid crystal color filter and fabricating method thereof
EP1697780A1 (en) * 2003-12-22 2006-09-06 Motorola, Inc., A Corporation of the State of Delaware; Dual mode display
US20060285037A1 (en) * 2005-06-21 2006-12-21 Chi Lin Technology Co., Ltd. Apparatus for mixing light beams and backlight module having the same
US20060290847A1 (en) * 2005-06-24 2006-12-28 Samsung Electronics Co., Ltd. Liquid crystal display
US20070035679A1 (en) * 2005-08-11 2007-02-15 Samsung Electronics Co., Ltd. Backlight unit and liquid crystal display having the same
US7184115B2 (en) 2002-01-07 2007-02-27 Moxtek, Inc. Display apparatus with two polarization compensators
US20070076295A1 (en) * 2005-09-30 2007-04-05 Rockwell Scientific Company Electronic adjustable color filter
US7221420B2 (en) 2002-01-07 2007-05-22 Sony Corporation Display with a wire grid polarizing beamsplitter
US20070121034A1 (en) * 1993-12-21 2007-05-31 3M Innovative Properties Company Display Incorporating Reflective Polarizer
US20070279755A1 (en) * 2006-06-01 2007-12-06 3M Innovative Properties Company Head-Up Display System
US7306338B2 (en) 1999-07-28 2007-12-11 Moxtek, Inc Image projection system with a polarizing beam splitter
US7375887B2 (en) 2001-03-27 2008-05-20 Moxtek, Inc. Method and apparatus for correcting a visible light beam using a wire-grid polarizer
US20090310042A1 (en) * 2008-06-16 2009-12-17 Marcial Vidal Illumination system and method with efficient polarization recovery
US20100171913A1 (en) * 2003-03-27 2010-07-08 Do Yeon Kim Dual display liquid crystal display device
US7789515B2 (en) 2007-05-17 2010-09-07 Moxtek, Inc. Projection device with a folded optical path and wire-grid polarizer
US7800823B2 (en) 2004-12-06 2010-09-21 Moxtek, Inc. Polarization device to polarize and further control light
US7852560B2 (en) 1993-12-21 2010-12-14 3M Innovative Properties Company Display incorporating reflective polarizer
US7961393B2 (en) 2004-12-06 2011-06-14 Moxtek, Inc. Selectively absorptive wire-grid polarizer
US20120147315A1 (en) * 2010-12-08 2012-06-14 Yao-Dong Ma Brightness and color enhancement film for LED TV and monitor
US8243004B2 (en) 2003-03-10 2012-08-14 Fergason Patent Properties, Llc Apparatus and method for preparing, storing, transmitting and displaying images
US8248696B2 (en) 2009-06-25 2012-08-21 Moxtek, Inc. Nano fractal diffuser
US8467128B2 (en) 2008-11-19 2013-06-18 Shanghai Lexvu Opto Microelectronics Technology Co., Ltd. Polarizing cube and method of fabricating the same
US8611007B2 (en) 2010-09-21 2013-12-17 Moxtek, Inc. Fine pitch wire grid polarizer
US8755113B2 (en) 2006-08-31 2014-06-17 Moxtek, Inc. Durable, inorganic, absorptive, ultra-violet, grid polarizer
US8873144B2 (en) 2011-05-17 2014-10-28 Moxtek, Inc. Wire grid polarizer with multiple functionality sections
US8913321B2 (en) 2010-09-21 2014-12-16 Moxtek, Inc. Fine pitch grid polarizer
US8913320B2 (en) 2011-05-17 2014-12-16 Moxtek, Inc. Wire grid polarizer with bordered sections
US8922890B2 (en) 2012-03-21 2014-12-30 Moxtek, Inc. Polarizer edge rib modification
US9348076B2 (en) 2013-10-24 2016-05-24 Moxtek, Inc. Polarizer with variable inter-wire distance
US9753193B2 (en) 2014-04-16 2017-09-05 Beam Engineering For Advanced Measurements Co. Methods and apparatus for human vision correction using diffractive waveplate lenses
US9976911B1 (en) 2015-06-30 2018-05-22 Beam Engineering For Advanced Measurements Co. Full characterization wavefront sensor
US9983479B2 (en) 2010-04-21 2018-05-29 Beam Engineering For Advanced Measurements Co. Fabrication of high efficiency, high quality, large area diffractive waveplates and arrays
US10031424B2 (en) 2010-04-21 2018-07-24 Beam Engineering For Advanced Measurements Co. Fabrication of high efficiency, high quality, large area diffractive waveplates and arrays
US10036886B2 (en) 2010-01-29 2018-07-31 Beam Engineering For Advanced Measurements Co. Broadband optics for manipulating light beams and images
US10107945B2 (en) 2013-03-01 2018-10-23 Beam Engineering For Advanced Measurements Co. Vector vortex waveplates
US10114239B2 (en) 2010-04-21 2018-10-30 Beam Engineering For Advanced Measurements Co. Waveplate lenses and methods for their fabrication
US10185182B2 (en) * 2013-03-03 2019-01-22 Beam Engineering For Advanced Measurements Co. Mechanical rubbing method for fabricating cycloidal diffractive waveplates
US10191296B1 (en) 2015-06-30 2019-01-29 Beam Engineering For Advanced Measurements Co. Laser pointer with reduced risk of eye injury
US10197715B1 (en) 2013-03-15 2019-02-05 Beam Engineering For Advanced Measurements Co. Methods of diffractive lens and mirror fabrication
US10274805B2 (en) 2017-06-13 2019-04-30 Beam Engineering For Advanced Measurements Co. Polarization-independent switchable lens system
US10423045B2 (en) 2016-11-14 2019-09-24 Beam Engineering For Advanced Measurements Co. Electro-optical diffractive waveplate beam shaping system
US10436957B2 (en) 2015-10-27 2019-10-08 Beam Engineering For Advanced Measurements Co. Broadband imaging with diffractive waveplate coated mirrors and diffractive waveplate objective lens
US11175441B1 (en) 2018-03-05 2021-11-16 Beam Engineering For Advanced Measurements Co. Polarization-independent diffractive optical structures
US11294240B2 (en) 2019-08-10 2022-04-05 Beam Engineering For Advanced Measurements Co. Diffractive waveplate devices that operate over a wide temperature range
US11366254B2 (en) 2010-01-29 2022-06-21 Beam Engineering For Advanced Measurements Co. High-efficiency wide-angle beam steering system

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2295916A (en) * 1994-12-09 1996-06-12 Central Research Lab Ltd A device for backlighting a liquid crystal panel
WO1998050818A1 (en) * 1997-05-08 1998-11-12 Seiko Epson Corporation Display device and electronic equipment made by using the same
CN1122869C (en) 1997-06-13 2003-10-01 精工爱普生株式会社 Display and electronic device
KR100497616B1 (en) * 1998-01-14 2005-09-30 삼성전자주식회사 Structure of an LCD device
EP1708512A1 (en) * 2005-03-31 2006-10-04 SONY DEUTSCHLAND GmbH Image generation unit with four primary colors
WO2019181247A1 (en) 2018-03-23 2019-09-26 富士フイルム株式会社 Cholesteric liquid crystal layer, laminated body, optically anisotropic body, reflective film, production method for cholesteric liquid crystal layer; forgery prevention medium, and determination method

Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4019808A (en) * 1973-06-09 1977-04-26 Fraunhofer-Gesellschaft Zur Forderung Der Angewandten Forschung E.V. Arrangement for a polychrome display
US4073571A (en) * 1976-05-05 1978-02-14 Hughes Aircraft Company Circularly polarized light source
US4232948A (en) * 1973-07-18 1980-11-11 Secretary Of State For Defence Liquid crystal display device
US4239349A (en) * 1973-06-09 1980-12-16 Scheffer Terry J Arrangement for a polychrome display
US4416514A (en) * 1980-11-10 1983-11-22 Polaroid Corporation Color filter
US4436392A (en) * 1983-01-03 1984-03-13 Minnesota Mining And Manufacturing Company Distortion correction for an overhead projector system
US4652101A (en) * 1984-04-13 1987-03-24 Grunwald Peter H Overhead projector
JPS6313019A (en) * 1986-07-04 1988-01-20 Hitachi Ltd Liquid crystal display device
US4770500A (en) * 1986-06-10 1988-09-13 Kaiser Aerospace And Electronics Corporation Method and apparatus for multi color display
US4832461A (en) * 1986-08-20 1989-05-23 Fujitsu Limited Projection-type multi-color liquid crystal display device
US4838655A (en) * 1987-01-09 1989-06-13 Hitachi, Ltd. Projector using guest-host liquid crystal cells for improved color purity
US4917465A (en) * 1989-03-28 1990-04-17 In Focus Systems, Inc. Color display system
US4987410A (en) * 1988-01-25 1991-01-22 Kaiser Aerospace & Electronics Corporation Multiple image forming apparatus
US5050966A (en) * 1988-07-06 1991-09-24 Kaiser Aerospace & Electronics Corporation Optical combiner collimating apparatus
US5122887A (en) * 1991-03-05 1992-06-16 Sayett Group, Inc. Color display utilizing twisted nematic LCDs and selective polarizers
US5124818A (en) * 1989-06-07 1992-06-23 In Focus Systems, Inc. LCD system having improved contrast ratio
US5159363A (en) * 1988-12-02 1992-10-27 Eastman Kodak Company Optical system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4017156A (en) * 1974-02-28 1977-04-12 Matsushita Electric Industrial Co., Ltd. Electro-optical display device
CH600366A5 (en) * 1976-05-20 1978-06-15 Ebauches Sa
US5082354A (en) * 1989-08-29 1992-01-21 Kaiser Aerospace And Electronics Corporation Optical switch and color selection assembly

Patent Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4019808A (en) * 1973-06-09 1977-04-26 Fraunhofer-Gesellschaft Zur Forderung Der Angewandten Forschung E.V. Arrangement for a polychrome display
US4239349A (en) * 1973-06-09 1980-12-16 Scheffer Terry J Arrangement for a polychrome display
US4232948A (en) * 1973-07-18 1980-11-11 Secretary Of State For Defence Liquid crystal display device
US4073571A (en) * 1976-05-05 1978-02-14 Hughes Aircraft Company Circularly polarized light source
US4416514A (en) * 1980-11-10 1983-11-22 Polaroid Corporation Color filter
US4436392A (en) * 1983-01-03 1984-03-13 Minnesota Mining And Manufacturing Company Distortion correction for an overhead projector system
US4652101A (en) * 1984-04-13 1987-03-24 Grunwald Peter H Overhead projector
US4770500A (en) * 1986-06-10 1988-09-13 Kaiser Aerospace And Electronics Corporation Method and apparatus for multi color display
US4756604A (en) * 1986-07-04 1988-07-12 Hitachi, Ltd. Liquid crystal device using a Fresnel collimating lens for improving uniformity of display contrast ratio
JPS6313019A (en) * 1986-07-04 1988-01-20 Hitachi Ltd Liquid crystal display device
US4832461A (en) * 1986-08-20 1989-05-23 Fujitsu Limited Projection-type multi-color liquid crystal display device
US4838655A (en) * 1987-01-09 1989-06-13 Hitachi, Ltd. Projector using guest-host liquid crystal cells for improved color purity
US4987410A (en) * 1988-01-25 1991-01-22 Kaiser Aerospace & Electronics Corporation Multiple image forming apparatus
US5050966A (en) * 1988-07-06 1991-09-24 Kaiser Aerospace & Electronics Corporation Optical combiner collimating apparatus
US5159363A (en) * 1988-12-02 1992-10-27 Eastman Kodak Company Optical system
US4917465A (en) * 1989-03-28 1990-04-17 In Focus Systems, Inc. Color display system
US5124818A (en) * 1989-06-07 1992-06-23 In Focus Systems, Inc. LCD system having improved contrast ratio
US5122887A (en) * 1991-03-05 1992-06-16 Sayett Group, Inc. Color display utilizing twisted nematic LCDs and selective polarizers

Non-Patent Citations (16)

* Cited by examiner, † Cited by third party
Title
Belayev et al., "Large Aperture Polarized Light Source and Novel Liquid Crystal Display Operating Modes," Japanese Journal of Applied Physics, pp. L634-L637 (Mar. 7, 1990).
Belayev et al., Large Aperture Polarized Light Source and Novel Liquid Crystal Display Operating Modes, Japanese Journal of Applied Physics, pp. L634 L637 (Mar. 7, 1990). *
Crooker et al., "A Color Display Using Polymer-Dispersed Chiral Liquid Crystals," SID 1990 Symposium Digest, pp. 214-216 (1990).
Crooker et al., A Color Display Using Polymer Dispersed Chiral Liquid Crystals, SID 1990 Symposium Digest, pp. 214 216 (1990). *
Haberle et al., "Crosslinkable Cholesteric LC-Silicones," Record of the International Display Research Conference, pp. 57-59 (1991).
Haberle et al., Crosslinkable Cholesteric LC Silicones, Record of the International Display Research Conference, pp. 57 59 (1991). *
Maurer et al., "Polarizing Color Filters Made from Cholesteric LC Silicones," SIC 1990 Symposium Digest, pp. 110-113 (1990).
Maurer et al., Polarizing Color Filters Made from Cholesteric LC Silicones, SIC 1990 Symposium Digest, pp. 110 113 (1990). *
Schadt et al., "New Liquid Crystal Polarized Color Projection Principle," Japanese Journal of Applied Physics, pp. 1974-1984 (Jul. 21, 1990).
Schadt et al., "Novel Polarized Liquid-Crystal Color Projection and New TN-LCD Operating Modes," SID 1990 Symposium Digest, pp. 324-326 (1990).
Schadt et al., New Liquid Crystal Polarized Color Projection Principle, Japanese Journal of Applied Physics, pp. 1974 1984 (Jul. 21, 1990). *
Schadt et al., Novel Polarized Liquid Crystal Color Projection and New TN LCD Operating Modes, SID 1990 Symposium Digest, pp. 324 326 (1990). *
Uchida, "Color LCDs: Technological Developments," Japan Display '83, pp. 202-205.
Uchida, "Multicolored liquid crystal displays," Optical Engineering, vol. 23, No. 3 (May/Jun. 1984), pp. 247-252.
Uchida, Color LCDs: Technological Developments, Japan Display 83, pp. 202 205. *
Uchida, Multicolored liquid crystal displays, Optical Engineering, vol. 23, No. 3 (May/Jun. 1984), pp. 247 252. *

Cited By (234)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6104447A (en) * 1990-06-11 2000-08-15 Reveo, Inc. Electro-optical backlighting panel for use in computer-based display systems and portable light projection device for use therewith
US5828427A (en) * 1990-06-11 1998-10-27 Reveo, Inc. Computer-based image display systems having direct and projection modes of viewing
US6188460B1 (en) * 1990-06-11 2001-02-13 Reveo, Inc. Image display panel having a backlighting structure and a single-layer pixelated aray of reflective-type spectral filtering elements where between light is recycled for producing color images with enhanced brightness
US6753044B2 (en) 1991-11-27 2004-06-22 Reveo, Inc. Coloring media having improved brightness and color characteristics
US6583827B2 (en) 1991-11-27 2003-06-24 Reveo, Inc. Electro-optical glazing structures having bi-directional control of electromagnetic radiation during total-reflection, semi-transparent and totally-transparent modes of operation
US6559903B2 (en) 1991-11-27 2003-05-06 Reveo, Inc. Non-absorptive electro-optical glazing structure employing composite infrared reflective polarizing filter
US6633354B2 (en) 1991-11-27 2003-10-14 Reveo, Inc. Spectrum-controllable reflective polarizers having electrically-switchable modes of operation
US6710823B2 (en) 1991-11-27 2004-03-23 Reveo, Inc. Electro-optical glazing structures having reflection and transparent modes of operation
US6671008B1 (en) 1991-11-27 2003-12-30 Reveo, Inc. Electro-optical glazing structures having scattering and transparent modes of operation and methods and apparatus for making the same
US5940150A (en) * 1991-11-27 1999-08-17 Reveo, Inc. Electro-optical glazing structures having total-reflection and transparent modes of operation for use in dynamical control of electromagnetic radiation
US5555114A (en) * 1992-11-30 1996-09-10 Sanyo Electric Co., Ltd. Liquid crystal display with reflective color filters
US5793456A (en) * 1993-01-11 1998-08-11 U.S. Philips Corporation Cholesteric polarizer and the manufacture thereof
US5721603A (en) * 1993-01-11 1998-02-24 U.S. Philips Corporation Illumination system and display device including such a system
US6160597A (en) * 1993-02-17 2000-12-12 Rolic Ag Optical component and method of manufacture
US6369869B2 (en) 1993-02-17 2002-04-09 Rolic A.G. Optical component and method of manufacture
US6717644B2 (en) 1993-02-17 2004-04-06 Rolic Ag Optical component and method of manufacture
US5514127A (en) * 1993-02-18 1996-05-07 Central Research Laboratories Limited Apparatus for irradiating an area with a controllable pattern of light
US5570210A (en) * 1993-05-06 1996-10-29 Fujitsu Limited Liquid crystal display device with directional backlight and image production capability in the light scattering mode
US5548422A (en) * 1993-06-28 1996-08-20 In Focus Systems, Inc. Notch filters with cholesteric polarizers with birefringent film and linear polarizer
US5946431A (en) * 1993-07-30 1999-08-31 Molecular Dynamics Multi-functional photometer with movable linkage for routing light-transmitting paths using reflective surfaces
US5408346A (en) * 1993-10-20 1995-04-18 Kaiser Electro-Optics, Inc. Optical collimating device employing cholesteric liquid crystal and a non-transmissive reflector
US5537233A (en) * 1993-11-25 1996-07-16 Sanyo Electric Co., Ltd. Direct-vision/projection type liquid-crystal display having light source at the edge of a gap between two liquid crystal panels
US6169590B1 (en) 1993-12-02 2001-01-02 Ois Optical Imaging Systems, Inc. Liquid crystal display with optical compensator
US5818615A (en) * 1993-12-02 1998-10-06 Ois Optical Imaging Systems, Inc. Liquid crystal display with patterned retardation films
US5828488A (en) 1993-12-21 1998-10-27 Minnesota Mining And Manufacturing Co. Reflective polarizer display
US20050122587A1 (en) * 1993-12-21 2005-06-09 3M Innovative Properties Company Optical polarizer
US6025897A (en) 1993-12-21 2000-02-15 3M Innovative Properties Co. Display with reflective polarizer and randomizing cavity
US20050270439A1 (en) * 1993-12-21 2005-12-08 3M Innovative Properties Company Display having a reflective polarizer
US6804058B1 (en) 1993-12-21 2004-10-12 3M Innovative Properties Company Electroluminescent light source and display incorporating same
US6096375A (en) 1993-12-21 2000-08-01 3M Innovative Properties Company Optical polarizer
US6543153B1 (en) 1993-12-21 2003-04-08 3M Innovative Properties Company Reflective polarizer having improved properties and optical display with improved reflective polarizer
US7852560B2 (en) 1993-12-21 2010-12-14 3M Innovative Properties Company Display incorporating reflective polarizer
US20070121034A1 (en) * 1993-12-21 2007-05-31 3M Innovative Properties Company Display Incorporating Reflective Polarizer
US20060262400A1 (en) * 1993-12-21 2006-11-23 3M Innovative Properties Company Optical polarizer
US20030164914A1 (en) * 1993-12-21 2003-09-04 3M Innovative Properties Company Brightness enhancing reflective polarizer
US5717422A (en) * 1994-01-25 1998-02-10 Fergason; James L. Variable intensity high contrast passive display
US5541745A (en) * 1994-01-25 1996-07-30 Fergason; James L. Illumination system for a display using cholesteric liquid crystal reflectors
WO1995020180A1 (en) * 1994-01-25 1995-07-27 Fergason James L Display system and method
US5532854A (en) * 1994-01-25 1996-07-02 Fergason; James L. Folded variable birefringerence zeroth order hybrid aligned liquid crystal apparatus
US5532852A (en) * 1994-02-23 1996-07-02 Kaiser Aerospace And Electronics Corporation High speed, high ambient viewability liquid crystal display assembly
US5801793A (en) * 1994-04-21 1998-09-01 Reveo, Inc. Backlighting construction for use in computer-based display systems having direct and projection viewing modes of operation
WO1995029427A1 (en) * 1994-04-21 1995-11-02 Reveo, Inc. Transportable computer systems having dual viewing modes
US20050007514A1 (en) * 1994-04-21 2005-01-13 Faris Sadeg M. Backlighting construction for use in computer-based display systems having direct and projection viewing modes of operation
US6414728B1 (en) 1994-04-21 2002-07-02 Reveo, Inc. Image display system having direct and projection viewing modes
US5751385A (en) * 1994-06-07 1998-05-12 Honeywell, Inc. Subtractive color LCD utilizing circular notch polarizers and including a triband or broadband filter tuned light source or dichroic sheet color polarizers
US6573961B2 (en) 1994-06-27 2003-06-03 Reveo, Inc. High-brightness color liquid crystal display panel employing light recycling therein
US6141069A (en) * 1994-07-27 2000-10-31 University Technology Corporation Liquid crystal phase modulator using a ferroelectric liquid crystal with a rotatable axis and cholesteric circular polarizers
US5835166A (en) * 1994-08-17 1998-11-10 Hall; Dennis R. Chiral nematic liquid crystal polarization modulated color display for stereoscopic viewing device
US5712694A (en) * 1994-09-16 1998-01-27 Kabushiki Kaisha Toshiba LCD comprising a light separating element including a cholesteric liquid crystal sheet
US5692226A (en) * 1994-09-28 1997-11-25 Hall; Dennis R. Stereoscopic recording systems utilizing chiral liquid crystals
US7110052B1 (en) * 1994-10-13 2006-09-19 Reveo, Inc. Backlighting construction for use in computer-based display systems having direct and projection viewing modes of operation
US7843418B2 (en) 1994-10-25 2010-11-30 Fergason Patent Properties, Llc Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US20080136762A1 (en) * 1994-10-25 2008-06-12 Fergason James L Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US20050093796A1 (en) * 1994-10-25 2005-05-05 Fergason James L. Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US20080259012A1 (en) * 1994-10-25 2008-10-23 Fergason James L Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US20080122771A1 (en) * 1994-10-25 2008-05-29 Fergason James L Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US7352347B2 (en) 1994-10-25 2008-04-01 Fergason Patent Properties, Llc Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US20090033607A1 (en) * 1994-10-25 2009-02-05 Fergason James L Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US7843416B2 (en) 1994-10-25 2010-11-30 Fergason Patent Properties, Llc Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
US7843417B2 (en) 1994-10-25 2010-11-30 Fergason Patent Properties, Llc Optical display system and method, active and passive dithering using birefringence, color image superpositioning and display enhancement with phase coordinated polarization switching
EP0713126A1 (en) * 1994-11-14 1996-05-22 F. Hoffmann-La Roche Ag Coloured display with electrically controllable liquid crystal filters disposed in series
KR100258048B1 (en) * 1994-11-14 2000-06-01 보러 롤란드 Color display with serially connected lc filters
US5686931A (en) * 1994-11-14 1997-11-11 Rolic Ag Device for displaying colors produced by controllable cholesteric color filters
CN1126980C (en) * 1994-11-14 2003-11-05 罗列克股份公司 Colour display with serially-connected LCD filters
US6094242A (en) * 1994-12-19 2000-07-25 Sharp Kabushiki Kaisha Optical device and head-mounted display using said optical device
US6304303B1 (en) 1994-12-19 2001-10-16 Sharp Kabushiki Kaisha Optical device and head-mounted display using said optical device
EP0718645A2 (en) * 1994-12-19 1996-06-26 Sharp Kabushiki Kaisha Optical device and head-mounted display using said optical device
EP0718645A3 (en) * 1994-12-19 1996-10-16 Sharp Kk Optical device and head-mounted display using said optical device
US5822029A (en) * 1994-12-29 1998-10-13 Sharp Kabushiki Kaisha Illumination system and display device
US6888675B2 (en) 1995-03-10 2005-05-03 3M Innovative Properties Company Transflective displays with reflective polarizing transflector
US20010008464A1 (en) * 1995-03-10 2001-07-19 3M Innovative Properties Company Transflective displays with reflective polarizing trasflector
US7511787B2 (en) * 1995-05-23 2009-03-31 Real D Color filters and sequencers using color-selective light modulators
US6882384B1 (en) * 1995-05-23 2005-04-19 Colorlink, Inc. Color filters and sequencers using color selective light modulators
US20050122454A1 (en) * 1995-05-23 2005-06-09 Colorlink, Inc. Color filters and sequencers using color-selective light modulators
US6088067A (en) * 1995-06-26 2000-07-11 3M Innovative Properties Company Liquid crystal display projection system using multilayer optical film polarizers
US5825542A (en) * 1995-06-26 1998-10-20 Minnesota Mining And Manufacturing Company Diffusely reflecting multilayer polarizers and mirrors
US6262842B1 (en) 1995-06-26 2001-07-17 3M Innovative Properties Company Transflective displays with reflective polarizing transflector
US6124971A (en) * 1995-06-26 2000-09-26 3M Innovative Properties Company Transflective displays with reflective polarizing transflector
US5686979A (en) * 1995-06-26 1997-11-11 Minnesota Mining And Manufacturing Company Optical panel capable of switching between reflective and transmissive states
US20020141194A1 (en) * 1995-06-26 2002-10-03 3M Innovative Properties Company Backlight system with multilayer optical film reflector
US6905220B2 (en) 1995-06-26 2005-06-14 3M Innovative Properties Company Backlight system with multilayer optical film reflector
US6018419A (en) * 1995-06-26 2000-01-25 3M Intellectual Properties Company Diffuse reflectors
US5831375A (en) * 1995-08-11 1998-11-03 Minnesota Mining And Manufacturing Company Electroluminescent lamp using multilayer optical film
US5856855A (en) * 1995-08-23 1999-01-05 U.S. Philips Corporation Edge-lit illumination system containing cholesteric polarizer and diffuser behind waveguide
US5808713A (en) * 1995-09-22 1998-09-15 U.S. Philips Corporation Flat-panel picture display device
US6404464B1 (en) 1995-10-30 2002-06-11 Reveo, Inc. Method and system for producing color images with improved brightness and color characteristics on radiation absorptive surfaces
WO1997020250A1 (en) * 1995-11-28 1997-06-05 Reveo, Inc. Image display systems having direct and projection viewing modes
US6104456A (en) * 1996-04-18 2000-08-15 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Liquid crystal display using circular polarized light and light emitting screen
US6130734A (en) * 1996-06-14 2000-10-10 Seiko Instruments Inc. Color LCD having particular parameters for LC layer, retarder, color polarizer align layer
US5841494A (en) * 1996-06-26 1998-11-24 Hall; Dennis R. Transflective LCD utilizing chiral liquid crystal filter/mirrors
US5799231A (en) * 1996-07-25 1998-08-25 International Business Machines Corporation Variable index distributed mirror
US6118504A (en) * 1996-08-23 2000-09-12 Seiko Epson Corporation Display device and electronic apparatus comprising the same
US6246506B1 (en) 1996-09-05 2001-06-12 Fujitsu Limited Optical display device having a reflection-type polarizer
US6111700A (en) * 1996-09-05 2000-08-29 Fujitsu Limited Optical display device having a reflection-type polarizer
WO1998011275A1 (en) * 1996-09-16 1998-03-19 Reveo, Inc. High-brightness color liquid crystal display panel employing systemic light recycling
US6333773B1 (en) 1996-09-16 2001-12-25 Reveo, Inc. Image display panel employing a broad-band polarizing/reflective backlighting structure and a pixelated array of reflective-type of filtering elements
US6738114B1 (en) 1996-11-04 2004-05-18 Reveo, Inc. Liquid crystal film structures with phase-retardation surface regions formed therein
US6078363A (en) * 1996-11-11 2000-06-20 Sharp Kabushiki Kaisha Image display apparatus
USRE40655E1 (en) * 1997-02-18 2009-03-10 Dai Nippon Printing Co., Ltd. Polarization light splitting film, backlight system and liquid crystal display having particular diffusion layer under optical rotational selection layer
US7342619B2 (en) * 1997-02-18 2008-03-11 Dai Nippon Printing Co., Ltd. Polarization light splitting film, backlight system and liquid crystal display
US6559911B2 (en) * 1997-02-18 2003-05-06 Dai Nippon Printing Co., Ltd. Polarization light splitting film, backlight system and liquid crystal display having particular diffusion layer under optical rotation selection layer
US20030164906A1 (en) * 1997-02-18 2003-09-04 Dai Nippon Printing Co., Ltd. Polarization light splitting film, backlight system and liquid crystal display
US6977695B2 (en) 1997-02-26 2005-12-20 Reveo, Inc. Variable optical attenuator based on electrically switchable cholesteric liquid crystal reflective polarizers
US20040141120A1 (en) * 1997-02-26 2004-07-22 Faris Sadeg M. Variable optical attenuator based on electrically switchable cholesteric liquid crystal reflective polarizers
US6034752A (en) * 1997-03-22 2000-03-07 Kent Displays Incorporated Display device reflecting visible and infrared radiation
US6377321B1 (en) 1997-03-22 2002-04-23 Kent Displays, Inc. Stacked color liquid crystal display device
US20050036077A1 (en) * 1997-03-22 2005-02-17 Khan Asad A. Stacked color liquid crystal display device
US7061559B2 (en) 1997-03-22 2006-06-13 Kent Displays, Inc. Stacked color liquid crystal display device
US6654080B1 (en) 1997-03-22 2003-11-25 Kent Displays, Inc. Stacked color liquid crystal display device
US5940152A (en) * 1997-05-01 1999-08-17 Wilson; Stephen S. Dual-fresnel field lens for a single-panel LCD projection system
US6417903B1 (en) * 1997-06-30 2002-07-09 Citizen Watch Co., Ltd. Liquid crystal display device
US6377325B2 (en) * 1997-07-09 2002-04-23 Sadeg M. Faris Reflective film material having symmetrical reflection characteristics and method and apparatus for making the same
EP0895116A3 (en) * 1997-07-31 1999-12-29 Compaq Computer Corporation Liquid crystal color shutters using reflective polarizer
EP0895116A2 (en) * 1997-07-31 1999-02-03 Compaq Computer Corporation Liquid crystal color shutters using reflective polarizer
US6888612B2 (en) * 1997-11-04 2005-05-03 Vrex, Inc. Liquid crystal film structures with phase-retardation surface regions formed therein
US20040246405A1 (en) * 1997-11-04 2004-12-09 Faris Sadeg M. Liquid crystal film structures with phase-retardation surface regions formed therein
US6612702B1 (en) * 1998-02-16 2003-09-02 Seiko Corporation Projection display device
US6637886B2 (en) 1998-02-16 2003-10-28 Seiko Epson Corporation Projection display device
US6118507A (en) * 1998-04-20 2000-09-12 Sony Corporation Reflection TN-ECB having particular relationships between perpendicular axis and oriented directions
US6710921B2 (en) 1998-05-14 2004-03-23 Moxtek Polarizer apparatus for producing a generally polarized beam of light
US6452724B1 (en) 1998-05-14 2002-09-17 Moxtek Polarizer apparatus for producing a generally polarized beam of light
US6108131A (en) * 1998-05-14 2000-08-22 Moxtek Polarizer apparatus for producing a generally polarized beam of light
US6208463B1 (en) 1998-05-14 2001-03-27 Moxtek Polarizer apparatus for producing a generally polarized beam of light
US6160663A (en) * 1998-10-01 2000-12-12 3M Innovative Properties Company Film confined to a frame having relative anisotropic expansion characteristics
US6075651A (en) * 1999-01-28 2000-06-13 Kaiser Electro-Optics, Inc. Compact collimating apparatus
WO2000045212A1 (en) * 1999-01-28 2000-08-03 Kaiser Electro-Optics, Inc. Compact collimating apparatus
US6532048B1 (en) * 1999-02-01 2003-03-11 Seiko Epson Corporation Display device and electronic device using the same
US6897936B1 (en) 1999-04-06 2005-05-24 Inventqjaya Sdn. Bhd Electro-optical glazing structures having scattering and transparent modes of operation
US20060001797A1 (en) * 1999-04-22 2006-01-05 3M Innovative Properties Company Optical devices using reflecting polarizing materials
US20050002098A1 (en) * 1999-04-22 2005-01-06 3M Innovative Properties Company Optical devices using reflecting polarizing materials
US6515785B1 (en) 1999-04-22 2003-02-04 3M Innovative Properties Company Optical devices using reflecting polarizing materials
US6934082B2 (en) 1999-04-22 2005-08-23 3M Innovative Properties Company Optical devices using reflecting polarizing materials
US6829071B2 (en) 1999-04-22 2004-12-07 3M Innovative Properties Company Optical devices using reflecting polarizing materials
US20010036013A1 (en) * 1999-04-22 2001-11-01 3M Innovative Properties Company Optical devices using reflecting polarizing materials
US20080013174A1 (en) * 1999-04-22 2008-01-17 3M Innovative Properties Company Optical devices using reflecting polarizing materials
US6122103A (en) * 1999-06-22 2000-09-19 Moxtech Broadband wire grid polarizer for the visible spectrum
US6288840B1 (en) 1999-06-22 2001-09-11 Moxtek Imbedded wire grid polarizer for the visible spectrum
US6666556B2 (en) 1999-07-28 2003-12-23 Moxtek, Inc Image projection system with a polarizing beam splitter
US7306338B2 (en) 1999-07-28 2007-12-11 Moxtek, Inc Image projection system with a polarizing beam splitter
US6447120B2 (en) 1999-07-28 2002-09-10 Moxtex Image projection system with a polarizing beam splitter
US6234634B1 (en) 1999-07-28 2001-05-22 Moxtek Image projection system with a polarizing beam splitter
US6243199B1 (en) 1999-09-07 2001-06-05 Moxtek Broad band wire grid polarizing beam splitter for use in the visible wavelength region
US6876403B1 (en) 1999-09-29 2005-04-05 Fujitsu General Limited Polarized light color filter and video projector comprising the same
WO2001023919A1 (en) * 1999-09-29 2001-04-05 Fujitsu General Limited Polarized light color filter and video projector comprising the same
WO2001025841A1 (en) * 1999-10-01 2001-04-12 Citizen Watch Co., Ltd. Liquid crystal display panel and electronic apparatus using it
US6508560B2 (en) 1999-10-22 2003-01-21 3M Innovative Properties Company Display apparatus with corrosion-resistant light directing film
US6357880B2 (en) 1999-10-22 2002-03-19 3M Innovative Properties Company Display apparatus with corrosion-resistant light directing film
US6626545B2 (en) 1999-10-22 2003-09-30 3M Innovative Properties Co Light directing construction having corrosion resistant feature
US6264336B1 (en) 1999-10-22 2001-07-24 3M Innovative Properties Company Display apparatus with corrosion-resistant light directing film
US20030058387A1 (en) * 2000-02-03 2003-03-27 Jurg Fuenfschilling Colour switch
US6729730B2 (en) 2000-02-04 2004-05-04 Seiko Epson Corporation Projector
US20040174500A1 (en) * 2000-02-04 2004-09-09 Seiko Epson Corporation Projector
US6923544B2 (en) 2000-02-04 2005-08-02 Seiko Epson Corporation Projector
US6646710B2 (en) * 2000-04-27 2003-11-11 Fuji Xerox Co., Ltd. Light modulator
US20020075434A1 (en) * 2000-06-26 2002-06-20 Yingqiu Jiang Cholesteric liquid crystal polarizing device
US6833891B2 (en) * 2000-06-26 2004-12-21 Reveo, Inc. Reflective liquid crystal display using cholesteric polymers
US6667794B2 (en) * 2000-09-25 2003-12-23 Fuji Photo Film Co., Ltd. Collimator utilizing wavelength selective reflection and backlight system
EP1203980A1 (en) * 2000-11-03 2002-05-08 Rolic AG Switchable color filter
US7126654B2 (en) * 2000-11-03 2006-10-24 Rolic Ag Switchable color filter
WO2002037176A1 (en) * 2000-11-03 2002-05-10 Rolic Ag Switchable color filter
KR100797805B1 (en) 2000-11-03 2008-01-24 롤리크 아게 Switchable color filter
US20050099373A1 (en) * 2000-11-03 2005-05-12 Jurg Funfschilling Switchable color filter
US7375887B2 (en) 2001-03-27 2008-05-20 Moxtek, Inc. Method and apparatus for correcting a visible light beam using a wire-grid polarizer
US6914654B2 (en) 2001-11-09 2005-07-05 Koninklijke Philips Electronics N.V. High contrast fast liquid crystal display system
WO2003040819A1 (en) * 2001-11-09 2003-05-15 Koninklijke Philips Electronics N.V. Fast fast liquid crystal display system with high contrast
US7221420B2 (en) 2002-01-07 2007-05-22 Sony Corporation Display with a wire grid polarizing beamsplitter
US7184115B2 (en) 2002-01-07 2007-02-27 Moxtek, Inc. Display apparatus with two polarization compensators
US6785050B2 (en) 2002-05-09 2004-08-31 Moxtek, Inc. Corrosion resistant wire-grid polarizer and method of fabrication
US7342627B2 (en) * 2002-10-31 2008-03-11 Lg.Philips Lcd. Co., Ltd. Liquid crystal display device using OCB mode and cholesteric liquid crystal color filter and fabricating method thereof
US20060187382A1 (en) * 2002-10-31 2006-08-24 Kim Gi-Hong Liquid crystal display device using cholesteric liquid crystal color filter and fabricating method thereof
US20040125449A1 (en) * 2002-12-30 2004-07-01 Sales Tasso R. Grid polarizer with suppressed reflectivity
US7113335B2 (en) 2002-12-30 2006-09-26 Sales Tasso R Grid polarizer with suppressed reflectivity
US20040135742A1 (en) * 2002-12-31 2004-07-15 Weber Michael F. Head-up display with polarized light source and wide-angle p-polarization reflective polarizer
US7123418B2 (en) 2002-12-31 2006-10-17 3M Innovative Properties Company Head-up display with narrow band reflective polarizer
US20050270655A1 (en) * 2002-12-31 2005-12-08 3M Innovative Properties Company Head-up display with narrow band reflective polarizer
US6952312B2 (en) 2002-12-31 2005-10-04 3M Innovative Properties Company Head-up display with polarized light source and wide-angle p-polarization reflective polarizer
US9847073B2 (en) 2003-03-10 2017-12-19 Fergason Licensing Llc Apparatus and method for preparing, storing, transmitting and displaying images
US8243004B2 (en) 2003-03-10 2012-08-14 Fergason Patent Properties, Llc Apparatus and method for preparing, storing, transmitting and displaying images
US9881588B2 (en) 2003-03-10 2018-01-30 Fergason Licensing Llc Apparatus and method for preparing, storing, transmitting and displaying images
US20100171913A1 (en) * 2003-03-27 2010-07-08 Do Yeon Kim Dual display liquid crystal display device
US8159638B2 (en) * 2003-03-27 2012-04-17 Lg Display Co., Ltd. Selective reflection/transmission optical device
US20050104027A1 (en) * 2003-10-17 2005-05-19 Lazarev Pavel I. Three-dimensional integrated circuit with integrated heat sinks
EP1697780A1 (en) * 2003-12-22 2006-09-06 Motorola, Inc., A Corporation of the State of Delaware; Dual mode display
EP1697780A4 (en) * 2003-12-22 2007-09-26 Motorola Inc Dual mode display
US20060066803A1 (en) * 2004-09-30 2006-03-30 Aylward Peter T Substrate free flexible liquid crystal displays
US7570424B2 (en) 2004-12-06 2009-08-04 Moxtek, Inc. Multilayer wire-grid polarizer
US7800823B2 (en) 2004-12-06 2010-09-21 Moxtek, Inc. Polarization device to polarize and further control light
US7813039B2 (en) 2004-12-06 2010-10-12 Moxtek, Inc. Multilayer wire-grid polarizer with off-set wire-grid and dielectric grid
US20060119937A1 (en) * 2004-12-06 2006-06-08 Moxtek, Inc. Multilayer wire-grid polarizer
US8027087B2 (en) 2004-12-06 2011-09-27 Moxtek, Inc. Multilayer wire-grid polarizer with off-set wire-grid and dielectric grid
US7961393B2 (en) 2004-12-06 2011-06-14 Moxtek, Inc. Selectively absorptive wire-grid polarizer
US20060285037A1 (en) * 2005-06-21 2006-12-21 Chi Lin Technology Co., Ltd. Apparatus for mixing light beams and backlight module having the same
US20060290847A1 (en) * 2005-06-24 2006-12-28 Samsung Electronics Co., Ltd. Liquid crystal display
US20070035679A1 (en) * 2005-08-11 2007-02-15 Samsung Electronics Co., Ltd. Backlight unit and liquid crystal display having the same
US20070076295A1 (en) * 2005-09-30 2007-04-05 Rockwell Scientific Company Electronic adjustable color filter
US20070279755A1 (en) * 2006-06-01 2007-12-06 3M Innovative Properties Company Head-Up Display System
US8755113B2 (en) 2006-08-31 2014-06-17 Moxtek, Inc. Durable, inorganic, absorptive, ultra-violet, grid polarizer
US7789515B2 (en) 2007-05-17 2010-09-07 Moxtek, Inc. Projection device with a folded optical path and wire-grid polarizer
US20090310042A1 (en) * 2008-06-16 2009-12-17 Marcial Vidal Illumination system and method with efficient polarization recovery
US8467128B2 (en) 2008-11-19 2013-06-18 Shanghai Lexvu Opto Microelectronics Technology Co., Ltd. Polarizing cube and method of fabricating the same
US8248696B2 (en) 2009-06-25 2012-08-21 Moxtek, Inc. Nano fractal diffuser
US11366254B2 (en) 2010-01-29 2022-06-21 Beam Engineering For Advanced Measurements Co. High-efficiency wide-angle beam steering system
US10120112B2 (en) 2010-01-29 2018-11-06 Beam Engineering For Advanced Measurements Co. Diffractive waveplate lenses for correcting aberrations and polarization-independent functionality
US10036886B2 (en) 2010-01-29 2018-07-31 Beam Engineering For Advanced Measurements Co. Broadband optics for manipulating light beams and images
US10557977B1 (en) 2010-01-29 2020-02-11 Beam Engineering For Advanced Measurements Co. Diffractive waveplate lenses and applications
US10274650B2 (en) 2010-01-29 2019-04-30 Beam Engineering For Advanced Measurements Co. Diffractive waveplate lenses and applications
US11366253B2 (en) 2010-01-29 2022-06-21 Beam Engineering For Advanced Measurements Co. Diffractive waveplate lenses and applications
US11119257B2 (en) 2010-04-21 2021-09-14 Beam Engineering For Advanced Measurements Co Methods of diffractive lens and mirror fabrication
US10802302B2 (en) 2010-04-21 2020-10-13 Beam Engineering For Advanced Measurements Co. Waveplate lenses and methods for their fabrication
US9983479B2 (en) 2010-04-21 2018-05-29 Beam Engineering For Advanced Measurements Co. Fabrication of high efficiency, high quality, large area diffractive waveplates and arrays
US10031424B2 (en) 2010-04-21 2018-07-24 Beam Engineering For Advanced Measurements Co. Fabrication of high efficiency, high quality, large area diffractive waveplates and arrays
US10114239B2 (en) 2010-04-21 2018-10-30 Beam Engineering For Advanced Measurements Co. Waveplate lenses and methods for their fabrication
US8913321B2 (en) 2010-09-21 2014-12-16 Moxtek, Inc. Fine pitch grid polarizer
US8611007B2 (en) 2010-09-21 2013-12-17 Moxtek, Inc. Fine pitch wire grid polarizer
US20120147315A1 (en) * 2010-12-08 2012-06-14 Yao-Dong Ma Brightness and color enhancement film for LED TV and monitor
US8363204B2 (en) * 2010-12-08 2013-01-29 MacroDisplay Inc. Brightness and color enhancement film for LED TV and monitor
US8913320B2 (en) 2011-05-17 2014-12-16 Moxtek, Inc. Wire grid polarizer with bordered sections
US8873144B2 (en) 2011-05-17 2014-10-28 Moxtek, Inc. Wire grid polarizer with multiple functionality sections
US8922890B2 (en) 2012-03-21 2014-12-30 Moxtek, Inc. Polarizer edge rib modification
US10107945B2 (en) 2013-03-01 2018-10-23 Beam Engineering For Advanced Measurements Co. Vector vortex waveplates
US10185182B2 (en) * 2013-03-03 2019-01-22 Beam Engineering For Advanced Measurements Co. Mechanical rubbing method for fabricating cycloidal diffractive waveplates
US10197715B1 (en) 2013-03-15 2019-02-05 Beam Engineering For Advanced Measurements Co. Methods of diffractive lens and mirror fabrication
US9632223B2 (en) 2013-10-24 2017-04-25 Moxtek, Inc. Wire grid polarizer with side region
US9348076B2 (en) 2013-10-24 2016-05-24 Moxtek, Inc. Polarizer with variable inter-wire distance
US9354374B2 (en) 2013-10-24 2016-05-31 Moxtek, Inc. Polarizer with wire pair over rib
US10191191B2 (en) 2014-04-16 2019-01-29 Beam Engineering For Advanced Measurements Co. Diffractive waveplate lenses and applications
US9753193B2 (en) 2014-04-16 2017-09-05 Beam Engineering For Advanced Measurements Co. Methods and apparatus for human vision correction using diffractive waveplate lenses
US10191296B1 (en) 2015-06-30 2019-01-29 Beam Engineering For Advanced Measurements Co. Laser pointer with reduced risk of eye injury
US9976911B1 (en) 2015-06-30 2018-05-22 Beam Engineering For Advanced Measurements Co. Full characterization wavefront sensor
US10436957B2 (en) 2015-10-27 2019-10-08 Beam Engineering For Advanced Measurements Co. Broadband imaging with diffractive waveplate coated mirrors and diffractive waveplate objective lens
US10423045B2 (en) 2016-11-14 2019-09-24 Beam Engineering For Advanced Measurements Co. Electro-optical diffractive waveplate beam shaping system
US10274805B2 (en) 2017-06-13 2019-04-30 Beam Engineering For Advanced Measurements Co. Polarization-independent switchable lens system
US11175441B1 (en) 2018-03-05 2021-11-16 Beam Engineering For Advanced Measurements Co. Polarization-independent diffractive optical structures
US11294240B2 (en) 2019-08-10 2022-04-05 Beam Engineering For Advanced Measurements Co. Diffractive waveplate devices that operate over a wide temperature range

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EP0677178B1 (en) 1998-05-20
WO1994016355A1 (en) 1994-07-21
TW273600B (en) 1996-04-01
DE69318729D1 (en) 1998-06-25
EP0677178A1 (en) 1995-10-18
KR960700458A (en) 1996-01-20
DE69318729T2 (en) 1998-12-10
JPH08505480A (en) 1996-06-11

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